core/thread: Support StackGrowsUp in getStackBottom()

Author: ibuclaw

src/core/thread.d

@@ -3256,7 +3256,9 @@ private void* getStackBottom() nothrow @nogc
         pthread_getattr_np(pthread_self(), &attr);
         pthread_attr_getstack(&attr, &addr, &size);
         pthread_attr_destroy(&attr);
-        return addr + size;
+        version (StackGrowsDown)
+            addr += size;
+        return addr;
     }
     else version (FreeBSD)
     {
@@ -3267,7 +3269,9 @@ private void* getStackBottom() nothrow @nogc
         pthread_attr_get_np(pthread_self(), &attr);
         pthread_attr_getstack(&attr, &addr, &size);
         pthread_attr_destroy(&attr);
-        return addr + size;
+        version (StackGrowsDown)
+            addr += size;
+        return addr;
     }
     else version (NetBSD)
     {
@@ -3278,7 +3282,9 @@ private void* getStackBottom() nothrow @nogc
         pthread_attr_get_np(pthread_self(), &attr);
         pthread_attr_getstack(&attr, &addr, &size);
         pthread_attr_destroy(&attr);
-        return addr + size;
+        version (StackGrowsDown)
+            addr += size;
+        return addr;
     }
     else version (DragonFlyBSD)
     {
@@ -3289,7 +3295,9 @@ private void* getStackBottom() nothrow @nogc
         pthread_attr_get_np(pthread_self(), &attr);
         pthread_attr_getstack(&attr, &addr, &size);
         pthread_attr_destroy(&attr);
-        return addr + size;
+        version (StackGrowsDown)
+            addr += size;
+        return addr;
     }
     else version (Solaris)
     {
@@ -3306,7 +3314,9 @@ private void* getStackBottom() nothrow @nogc
         pthread_getattr_np(pthread_self(), &attr);
         pthread_attr_getstack(&attr, &addr, &size);
         pthread_attr_destroy(&attr);
-        return addr + size;
+        version (StackGrowsDown)
+            addr += size;
+        return addr;
     }
     else version (CRuntime_Musl)
     {
@@ -3316,7 +3326,9 @@ private void* getStackBottom() nothrow @nogc
         pthread_getattr_np(pthread_self(), &attr);
         pthread_attr_getstack(&attr, &addr, &size);
         pthread_attr_destroy(&attr);
-        return addr + size;
+        version (StackGrowsDown)
+            addr += size;
+        return addr;
     }
     else version (CRuntime_UClibc)
     {
@@ -3326,7 +3338,9 @@ private void* getStackBottom() nothrow @nogc
         pthread_getattr_np(pthread_self(), &attr);
         pthread_attr_getstack(&attr, &addr, &size);
         pthread_attr_destroy(&attr);
-        return addr + size;
+        version (StackGrowsDown)
+            addr += size;
+        return addr;
     }
     else
         static assert(false, "Platform not supported.");