Ensure we are UsingTheRightCompiler (https://trac.macports.org/wiki/UsingTheRightCompiler).
Ensure we always use -m32/-m64 and -arch for all architectures.
--- mono/mini/aot-compiler.c.orig	2019-01-17 00:45:20.000000000 -0700
+++ mono/mini/aot-compiler.c	2019-02-18 05:59:15.000000000 -0700
@@ -11876,6 +11876,8 @@
 #define AS_OPTIONS "-xarch=v9"
 #elif defined(TARGET_X86) && defined(TARGET_MACH)
 #define AS_OPTIONS "-arch i386"
+#elif defined(TARGET_AMD64) && defined(TARGET_MACH)
+#define AS_OPTIONS "-arch x86_64"
 #elif defined(TARGET_X86) && !defined(TARGET_MACH)
 #define AS_OPTIONS "--32"
 #else
@@ -11883,7 +11885,7 @@
 #endif
 
 #if defined(TARGET_OSX)
-#define AS_NAME "clang"
+#define AS_NAME "__MACPORTS_CC__"
 #elif defined(TARGET_WIN32_MSVC)
 #define AS_NAME "clang.exe"
 #else
@@ -11900,11 +11902,14 @@
 #define LD_NAME "ld"
 #define LD_OPTIONS "-shared -G"
 #elif defined(__ppc__) && defined(TARGET_MACH)
-#define LD_NAME "gcc"
-#define LD_OPTIONS "-dynamiclib"
+#define LD_NAME "__MACPORTS_CC__"
+#define LD_OPTIONS "-m32 -dynamiclib"
+#elif defined(__ppc64__) && defined(TARGET_MACH)
+#define LD_NAME "__MACPORTS_CC__"
+#define LD_OPTIONS "-m64 -dynamiclib"
 #elif defined(TARGET_AMD64) && defined(TARGET_MACH)
-#define LD_NAME "clang"
-#define LD_OPTIONS "--shared"
+#define LD_NAME "__MACPORTS_CC__"
+#define LD_OPTIONS "-m64 --shared"
 #elif defined(TARGET_WIN32_MSVC)
 #define LD_NAME "link.exe"
 #define LD_OPTIONS "/DLL /MACHINE:X64 /NOLOGO /INCREMENTAL:NO"
@@ -11913,7 +11918,7 @@
 #define LD_NAME "gcc"
 #define LD_OPTIONS "-shared"
 #elif defined(TARGET_X86) && defined(TARGET_MACH)
-#define LD_NAME "clang"
+#define LD_NAME "__MACPORTS_CC__"
 #define LD_OPTIONS "-m32 -dynamiclib"
 #elif defined(TARGET_X86) && !defined(TARGET_MACH)
 #define LD_OPTIONS "-m elf_i386"