Fix x86 build, tweak MSVC opt flags.

Use:

/Ot /Oy /Ob3 /GF /Gy

, instead of /O2 for x86, this makes it not crash on ROM load for the
OpenGL renderer.

Supposedly /O2 is equivalent to:

/Og /Oi /Ot /Oy /Ob2 /GF /Gy

, but the documentation states that /Og is automatically enabled when
any other optimizations are enabled automatically. So this should make
absolutely no difference, yet it does.

For x64 use:

/O2 /Ob3

, this overrides /Ob2 from /O2 to use more aggressive inlining, VS 2019
is required for this.

Signed-off-by: Rafael Kitover <rkitover@gmail.com>

CMakeLists.txt

@@ -749,7 +749,14 @@ elseif(MSVC)
     if(CMAKE_BUILD_TYPE STREQUAL Debug)
         add_compile_options(/W4)
     else()
-        add_compile_options(/w /O2)
+        add_compile_options(/w)
+
+        if(X86_32)
+            add_compile_options(/Ot /Oy /Ob3 /GF /Gy)
+        else()
+            add_compile_options(/O2 /Ob3)
+        endif()
+
 
         if(ENABLE_LTO)
             add_compile_options(/GL)