Merge pull request #2365 from n8sh/zero-init-TempStringNoAlloc

Make TempStringNoAlloc zero-init + avoid unnecessary init
merged-on-behalf-of: Jacob Carlborg <jacob-carlborg@users.noreply.github.com>

Author: dlang-bot

src/core/demangle.d

@@ -277,7 +277,7 @@ pure @safe:
     {
         import core.internal.string;
 
-        UnsignedStringBuf buf;
+        UnsignedStringBuf buf = void;
 
         auto s = unsignedToTempString(val, buf, 16);
         int slen = cast(int)s.length;

src/core/internal/abort.d

@@ -37,7 +37,7 @@ void abort(scope string msg, scope string filename = __FILE__, size_t line = __L
         static assert(0, "Unsupported OS");
 
     import core.internal.string;
-    UnsignedStringBuf strbuff;
+    UnsignedStringBuf strbuff = void;
 
     // write an appropriate message, then abort the program
     writeStr("Aborting from ", filename, "(", line.unsignedToTempString(strbuff, 10), ") ", msg);

src/core/internal/string.d

@@ -56,7 +56,7 @@ char[] unsignedToTempString()(ulong value, return scope char[] buf, uint radix =
 private struct TempStringNoAlloc
 {
     // need to handle 65 bytes for radix of 2 with negative sign.
-    private char[65] _buf;
+    private char[65] _buf = void;
     private ubyte _len;
     auto get() return
     {