Use C/C++ bool type to implement EM_BOOL (#22157)

This reduces the size of several structs and can result in code size
savings in some cases. The reason
the code size savings don't show up in trivial examples is (I believe)
because this change also increases
the use of HEAP8 (where previously some examples only depended on
HEAP32).

This change is split of from a larger change I have planned to remove
the use of EM_BOOL completely: #22155.

Author: sbc100

ChangeLog.md

@@ -20,6 +20,8 @@ See docs/process.md for more on how version tagging works.
 
 3.1.62 (in development)
 -----------------------
+- The `EM_BOOL` type changed from `int/u32` to `bool/u8`.  This changes the
+  layout and size of some structs in the emscripten API. (#22157)
 - The `EMSCRIPTEN_FETCH_WAITABLE` flag along with the `emscripten_fetch_wait`
   API were marked a deprecated.  These feature have not functions for several
   years now. (#22138)

src/generated_struct_info32.json

@@ -493,15 +493,15 @@
             "nodeName": 0
         },
         "EmscriptenFullscreenChangeEvent": {
-            "__size__": 280,
-            "elementHeight": 268,
-            "elementWidth": 264,
-            "fullscreenEnabled": 4,
-            "id": 136,
+            "__size__": 276,
+            "elementHeight": 264,
+            "elementWidth": 260,
+            "fullscreenEnabled": 1,
+            "id": 130,
             "isFullscreen": 0,
-            "nodeName": 8,
-            "screenHeight": 276,
-            "screenWidth": 272
+            "nodeName": 2,
+            "screenHeight": 272,
+            "screenWidth": 268
         },
         "EmscriptenFullscreenStrategy": {
             "__size__": 24,
@@ -513,53 +513,53 @@
             "scaleMode": 0
         },
         "EmscriptenGamepadEvent": {
-            "__size__": 1432,
+            "__size__": 1240,
             "analogButton": 528,
             "axis": 16,
-            "connected": 1296,
+            "connected": 1104,
             "digitalButton": 1040,
-            "id": 1304,
-            "index": 1300,
-            "mapping": 1368,
+            "id": 1112,
+            "index": 1108,
+            "mapping": 1176,
             "numAxes": 8,
             "numButtons": 12,
             "timestamp": 0
         },
         "EmscriptenKeyboardEvent": {
-            "__size__": 176,
-            "altKey": 20,
-            "charCode": 32,
-            "charValue": 108,
-            "code": 76,
+            "__size__": 160,
+            "altKey": 14,
+            "charCode": 20,
+            "charValue": 96,
+            "code": 64,
             "ctrlKey": 12,
-            "key": 44,
-            "keyCode": 36,
-            "locale": 140,
+            "key": 32,
+            "keyCode": 24,
+            "locale": 128,
             "location": 8,
-            "metaKey": 24,
-            "repeat": 28,
-            "shiftKey": 16,
+            "metaKey": 15,
+            "repeat": 16,
+            "shiftKey": 13,
             "timestamp": 0,
-            "which": 40
+            "which": 28
         },
         "EmscriptenMouseEvent": {
-            "__size__": 72,
-            "altKey": 32,
-            "button": 40,
-            "buttons": 42,
-            "canvasX": 60,
-            "canvasY": 64,
+            "__size__": 64,
+            "altKey": 26,
+            "button": 28,
+            "buttons": 30,
+            "canvasX": 48,
+            "canvasY": 52,
             "clientX": 16,
             "clientY": 20,
             "ctrlKey": 24,
-            "metaKey": 36,
-            "movementX": 44,
-            "movementY": 48,
+            "metaKey": 27,
+            "movementX": 32,
+            "movementY": 36,
             "screenX": 8,
             "screenY": 12,
-            "shiftKey": 28,
-            "targetX": 52,
-            "targetY": 56,
+            "shiftKey": 25,
+            "targetX": 40,
+            "targetY": 44,
             "timestamp": 0
         },
         "EmscriptenOrientationChangeEvent": {
@@ -568,36 +568,36 @@
             "orientationIndex": 0
         },
         "EmscriptenPointerlockChangeEvent": {
-            "__size__": 260,
-            "id": 132,
+            "__size__": 257,
+            "id": 129,
             "isActive": 0,
-            "nodeName": 4
+            "nodeName": 1
         },
         "EmscriptenTouchEvent": {
-            "__size__": 1696,
-            "altKey": 20,
+            "__size__": 1552,
+            "altKey": 14,
             "ctrlKey": 12,
-            "metaKey": 24,
+            "metaKey": 15,
             "numTouches": 8,
-            "shiftKey": 16,
+            "shiftKey": 13,
             "timestamp": 0,
-            "touches": 28
+            "touches": 16
         },
         "EmscriptenTouchPoint": {
-            "__size__": 52,
-            "canvasX": 44,
-            "canvasY": 48,
+            "__size__": 48,
+            "canvasX": 40,
+            "canvasY": 44,
             "clientX": 12,
             "clientY": 16,
             "identifier": 0,
             "isChanged": 28,
-            "onTarget": 32,
+            "onTarget": 29,
             "pageX": 20,
             "pageY": 24,
             "screenX": 4,
             "screenY": 8,
-            "targetX": 36,
-            "targetY": 40
+            "targetX": 32,
+            "targetY": 36
         },
         "EmscriptenUiEvent": {
             "__size__": 36,
@@ -617,26 +617,26 @@
             "visibilityState": 4
         },
         "EmscriptenWebGLContextAttributes": {
-            "__size__": 56,
+            "__size__": 36,
             "alpha": 0,
-            "antialias": 12,
-            "depth": 4,
-            "enableExtensionsByDefault": 40,
-            "explicitSwapControl": 44,
-            "failIfMajorPerformanceCaveat": 28,
-            "majorVersion": 32,
-            "minorVersion": 36,
-            "powerPreference": 24,
-            "premultipliedAlpha": 16,
-            "preserveDrawingBuffer": 20,
-            "proxyContextToMainThread": 48,
-            "renderViaOffscreenBackBuffer": 52,
-            "stencil": 8
+            "antialias": 3,
+            "depth": 1,
+            "enableExtensionsByDefault": 24,
+            "explicitSwapControl": 25,
+            "failIfMajorPerformanceCaveat": 12,
+            "majorVersion": 16,
+            "minorVersion": 20,
+            "powerPreference": 8,
+            "premultipliedAlpha": 4,
+            "preserveDrawingBuffer": 5,
+            "proxyContextToMainThread": 28,
+            "renderViaOffscreenBackBuffer": 32,
+            "stencil": 2
         },
         "EmscriptenWebSocketCloseEvent": {
-            "__size__": 524,
-            "code": 8,
-            "reason": 10,
+            "__size__": 520,
+            "code": 6,
+            "reason": 8,
             "wasClean": 4
         },
         "EmscriptenWebSocketCreateAttributes": {
@@ -650,11 +650,11 @@
             "numBytes": 8
         },
         "EmscriptenWheelEvent": {
-            "__size__": 104,
-            "deltaMode": 96,
-            "deltaX": 72,
-            "deltaY": 80,
-            "deltaZ": 88,
+            "__size__": 96,
+            "deltaMode": 88,
+            "deltaX": 64,
+            "deltaY": 72,
+            "deltaZ": 80,
             "mouse": 0
         },
         "SDL_AudioSpec": {