Properly detect SSE instruction support in 32-bit MSVC build. (#5943)

docs/CHANGELOG.txt

@@ -47,6 +47,7 @@ Other changes:
   clipping region. Regression added in 1.89. (#5720, #5919)
 - Misc: fixed parameters to IMGUI_DEBUG_LOG() not being dead-stripped when building
   with IMGUI_DISABLE_DEBUG_TOOLS is used. (#5901) [@Teselka]
+- Misc: fixed compile-time detection of SSE features on MSVC 32-bits builds. (#5943) [@TheMostDiligent]
 - Backends: Allegro5: restoring using al_draw_indexed_prim() when Allegro version is >= 5.2.5. (#5937) [@Espyo]
 
 

imgui_internal.h

@@ -56,7 +56,7 @@ Index of this file:
 #include <limits.h>     // INT_MIN, INT_MAX
 
 // Enable SSE intrinsics if available
-#if (defined __SSE__ || defined __x86_64__ || defined _M_X64) && !defined(IMGUI_DISABLE_SSE)
+#if (defined __SSE__ || defined __x86_64__ || defined _M_X64 || (defined(_M_IX86_FP) && (_M_IX86_FP >= 1))) && !defined(IMGUI_DISABLE_SSE)
 #define IMGUI_ENABLE_SSE
 #include <immintrin.h>
 #endif