Fixed FMA detection macro on msvc
Fixes
# endif
# if defined(__AVX2__)
# define SIMDE_ARCH_X86_AVX2 1
+# if defined(_MSC_VER)
+# define SIMDE_ARCH_X86_FMA 1
+# endif
# endif
# if defined(__FMA__)
# define SIMDE_ARCH_X86_FMA 1
