Take advantage of Triple and TargetData.

A lot of system specific knowledge is already present in LLVM. This is used to populate several fields in global.params instead of hard coded values in main(). Ensures that the frontend and LLVM have always the same values.

dmd/mars.h

@@ -71,6 +71,10 @@ the target object file format:
 #include <stddef.h>
 #include <stdarg.h>
 
+#if IN_LLVM
+#include "llvm/ADT/Triple.h"
+#endif
+
 #ifdef __DMC__
 #ifdef DEBUG
 #undef assert
@@ -140,14 +144,15 @@ struct OutBuffer;
 // LDC
 enum ARCH
 {
-    ARCHinvalid,
-    ARCHx86,
-    ARCHx86_64,
-    ARCHppc,
-    ARCHppc_64,
-    ARCHarm,
-    ARCHthumb
+    ARCHinvalid = llvm::Triple::UnknownArch,
+    ARCHx86 = llvm::Triple::x86,
+    ARCHx86_64 = llvm::Triple::x86_64,
+    ARCHppc = llvm::Triple::ppc,
+    ARCHppc_64 = llvm::Triple::ppc64,
+    ARCHarm = llvm::Triple::arm,
+    ARCHthumb = llvm::Triple::thumb,
 };
+
 enum OUTPUTFLAG
 {
     OUTPUTFLAGno,
@@ -157,13 +162,13 @@ enum OUTPUTFLAG
 
 enum OS
 {
-    OSinvalid,
-    OSLinux,
-    OSHaiku,
-    OSWindows,
-    OSMacOSX,
-    OSFreeBSD,
-    OSSolaris,
+    OSinvalid = llvm::Triple::UnknownOS,
+    OSLinux = llvm::Triple::Linux,
+    OSHaiku = llvm::Triple::Haiku,
+    OSWindows = llvm::Triple::Win32,
+    OSMacOSX = llvm::Triple::MacOSX,
+    OSFreeBSD = llvm::Triple::FreeBSD,
+    OSSolaris = llvm::Triple::Solaris,
 };
 
 typedef unsigned char ubyte;
@@ -303,8 +308,7 @@ struct Param
     bool useAvailableExternally;
 
     // target stuff
-    const char* llvmArch;
-    const char *targetTriple;
+    llvm::Triple *targetTriple;
 
     // Codegen cl options
     bool singleObj;