[glib/glib-2-64: 1/2] Define G_MSVC_SYMBOL_PREFIX correctly for ARM32

[Sebastian Dröge <sdroege src gnome org>]

commit c444a1aec78926cbeaebe41b03400cd4cc3317fa
Author: Wolfgang Stöggl <c72578 yahoo de>
Date:   Mon Oct 28 09:09:51 2019 +0100

    Define G_MSVC_SYMBOL_PREFIX correctly for ARM32
    
    Symbols on x86 are prefixed with an underscore
    but symbols on x64/ARM/ARM64 are not.
    
    Relevant information concerning the prefixes for the architectures
    can be found in the vcpkg project [1,2], where arm and arm64 builds
    are part of the CI.
    
    Specifically, _WIN64 is defined on Windows ARM64, so this issue is
    only visible when building on ARM32.
    
    [1] 
https://github.com/microsoft/vcpkg/blob/08e74979df124d9360343751cefcae615c2ec5ed/ports/glib/fix-arm-builds.patch
    [2] https://github.com/microsoft/vcpkg/pull/6116

 glib/gconstructor.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/glib/gconstructor.h b/glib/gconstructor.h
index 9509e595f..407202167 100644
--- a/glib/gconstructor.h
+++ b/glib/gconstructor.h
@@ -42,13 +42,13 @@
  */
 
 /* We need to account for differences between the mangling of symbols
- * for Win32 (x86) and x64 programs, as symbols on Win32 are prefixed
- * with an underscore but symbols on x64 are not.
+ * for x86 and x64/ARM/ARM64 programs, as symbols on x86 are prefixed
+ * with an underscore but symbols on x64/ARM/ARM64 are not.
  */
-#ifdef _WIN64
-#define G_MSVC_SYMBOL_PREFIX ""
-#else
+#ifdef _M_IX86
 #define G_MSVC_SYMBOL_PREFIX "_"
+#else
+#define G_MSVC_SYMBOL_PREFIX ""
 #endif
 
 #define G_DEFINE_CONSTRUCTOR(_func) G_MSVC_CTOR (_func, G_MSVC_SYMBOL_PREFIX)