[MIPS] Add support for direct-to-nacl in Clang

lib/Basic/Targets.cpp

Index: lib/Basic/Targets.cpp
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 6135f04b450a8e65d9c2e0c561a0d8bcc640c464..5c0fa423a3d415b48b81b1cfc8e225cbcdc0cf0f 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -6565,6 +6565,19 @@ void PNaClTargetInfo::getGCCRegAliases(const GCCRegAlias *&Aliases,
   NumAliases = 0;
 }
 
+// We attempt to use PNaCl (le32) frontend and Mips32EL backend.
+class NaClMips32ELTargetInfo : public Mips32ELTargetInfo {
+public:
+  NaClMips32ELTargetInfo(const llvm::Triple &Triple) :
+    Mips32ELTargetInfo(Triple)  {
+      MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
+  }
+
+  BuiltinVaListKind getBuiltinVaListKind() const override {
+    return TargetInfo::PNaClABIBuiltinVaList;
+  }
+};
+
 class Le64TargetInfo : public TargetInfo {
   static const Builtin::Info BuiltinInfo[];
 
@@ -6931,7 +6944,7 @@ static TargetInfo *AllocateTarget(const llvm::Triple &Triple) {
     case llvm::Triple::NetBSD:
       return new NetBSDTargetInfo<Mips32ELTargetInfo>(Triple);
     case llvm::Triple::NaCl:
-      return new NaClTargetInfo<Mips32ELTargetInfo>(Triple);
+      return new NaClTargetInfo<NaClMips32ELTargetInfo>(Triple);
     default:
       return new Mips32ELTargetInfo(Triple);
     }