Add register Mips::GP to the list of reserved registers if target is bare-metal
to prevent it from being clobbered. mips uses $gp to access small data section.

This bug was originally reported by Carl Norum.

llvm-svn: 162340
diff --git a/llvm/lib/Target/Mips/MipsTargetMachine.cpp b/llvm/lib/Target/Mips/MipsTargetMachine.cpp
index 2928a73..b70542b 100644
--- a/llvm/lib/Target/Mips/MipsTargetMachine.cpp
+++ b/llvm/lib/Target/Mips/MipsTargetMachine.cpp
@@ -42,7 +42,7 @@
                   CodeGenOpt::Level OL,
                   bool isLittle)
   : LLVMTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL),
-    Subtarget(TT, CPU, FS, isLittle),
+    Subtarget(TT, CPU, FS, isLittle, RM),
     DataLayout(isLittle ?
                (Subtarget.isABI_N64() ?
                 "e-p:64:64:64-i8:8:32-i16:16:32-i64:64:64-f128:128:128-n32" :