Common: Remove unused SSE version checking and a GCC macro.

src/common/platform.h

@@ -62,28 +62,3 @@
 #elif defined(__i386) || defined(_M_IX86) || defined(__arm__) || defined(_M_ARM)
     #define EMU_ARCH_BITS 32
 #endif
-
-////////////////////////////////////////////////////////////////////////////////////////////////////
-// Feature detection
-
-#if defined _M_GENERIC
-#  define _M_SSE 0x0
-#elif defined __GNUC__
-# if defined __SSE4_2__
-#  define _M_SSE 0x402
-# elif defined __SSE4_1__
-#  define _M_SSE 0x401
-# elif defined __SSSE3__
-#  define _M_SSE 0x301
-# elif defined __SSE3__
-#  define _M_SSE 0x300
-# endif
-#elif (_MSC_VER >= 1500) || __INTEL_COMPILER // Visual Studio 2008
-#  define _M_SSE 0x402
-#endif
-
-////////////////////////////////////////////////////////////////////////////////////////////////////
-// Compiler-Specific Definitions
-
-#define GCC_VERSION_AVAILABLE(major, minor) (defined(__GNUC__) &&  (__GNUC__ > (major) || \
-    (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))))