DRTVWR-418: Replace preprocessor tests for Windows-specific _M_AMD64

with tests on ADDRESS_SIZE, which is now set on the compiler command line.

indra/llcommon/llpreprocessor.h

@@ -139,7 +139,7 @@
 #pragma warning (disable : 4180)	// qualifier applied to function type has no meaning; ignored
 //#pragma warning( disable : 4284 )	// silly MS warning deep inside their <map> include file
 
-#ifdef _M_AMD64
+#if ADDRESS_SIZE == 64
 // That one is all over the place for x64 builds.
 #pragma warning( disable : 4267 )   // 'var' : conversion from 'size_t' to 'type', possible loss of data)
 #endif

indra/llmath/llmath.h

@@ -153,7 +153,7 @@ inline F64 llabs(const F64 a)
 
 inline S32 lltrunc( F32 f )
 {
-#if LL_WINDOWS && !defined( __INTEL_COMPILER ) && !defined( _M_AMD64 )
+#if LL_WINDOWS && !defined( __INTEL_COMPILER ) && (ADDRESS_SIZE == 32)
 		// Avoids changing the floating point control word.
 		// Add or subtract 0.5 - epsilon and then round
 		const static U32 zpfp[] = { 0xBEFFFFFF, 0x3EFFFFFF };
@@ -179,7 +179,7 @@ inline S32 lltrunc( F64 f )
 
 inline S32 llfloor( F32 f )
 {
-#if LL_WINDOWS && !defined( __INTEL_COMPILER ) && !defined( _M_AMD64 )
+#if LL_WINDOWS && !defined( __INTEL_COMPILER ) && (ADDRESS_SIZE == 32)
 		// Avoids changing the floating point control word.
 		// Accurate (unlike Stereopsis version) for all values between S32_MIN and S32_MAX and slightly faster than Stereopsis version.
 		// Add -(0.5 - epsilon) and then round

indra/llmath/llsimdmath.h

@@ -31,7 +31,7 @@
 #error "Please include llmath.h before this file."
 #endif
 
-#if ( ( LL_DARWIN || LL_LINUX ) && !(__SSE2__) ) || ( LL_WINDOWS && ( _M_IX86_FP < 2 && !_M_AMD64 ) )
+#if ( ( LL_DARWIN || LL_LINUX ) && !(__SSE2__) ) || ( LL_WINDOWS && ( _M_IX86_FP < 2 && ADDRESS_SIZE == 32 ) )
 #error SSE2 not enabled. LLVector4a and related class will not compile.
 #endif