Emit ARM build-attributes in the file scope (as header).

The ARM linker will check that .o files declare compatible
build attributes (e.g., all claim hard-float calling convention,
all claim VFP-vX ,etc.). Thus, in order to set up cross tests that
link LLC generated code against and Subzero generated code,
we need the build attributes to be compatible.

Pick ARMv7, hard-float calling convention, and neon, etc. which
we use for PNaCl LLVM.

Will probably have to reorganize to keep in sync once the ELF
writer also emits this.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4076
R=kschimpf@google.com, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1171563002.

src/IceTargetLoweringMIPS32.h

diff --git a/src/IceTargetLoweringMIPS32.h b/src/IceTargetLoweringMIPS32.h
index cb583b5..b6c325a 100644
--- a/src/IceTargetLoweringMIPS32.h
+++ b/src/IceTargetLoweringMIPS32.h
@@ -56,18 +56,23 @@
 
   const char *getConstantPrefix() const final { return ""; }
   void emit(const ConstantUndef *C) const final {
+    (void)C;
     llvm::report_fatal_error("Not yet implemented");
   }
   void emit(const ConstantInteger32 *C) const final {
+    (void)C;
     llvm::report_fatal_error("Not yet implemented");
   }
   void emit(const ConstantInteger64 *C) const final {
+    (void)C;
     llvm::report_fatal_error("Not yet implemented");
   }
   void emit(const ConstantFloat *C) const final {
+    (void)C;
     llvm::report_fatal_error("Not yet implemented");
   }
   void emit(const ConstantDouble *C) const final {
+    (void)C;
     llvm::report_fatal_error("Not yet implemented");
   }
 
@@ -128,8 +133,8 @@
   TargetDataMIPS32 &operator=(const TargetDataMIPS32 &) = delete;
 
 public:
-  static TargetDataLowering *create(GlobalContext *Ctx) {
-    return new TargetDataMIPS32(Ctx);
+  static std::unique_ptr<TargetDataLowering> create(GlobalContext *Ctx) {
+    return std::unique_ptr<TargetDataLowering>(new TargetDataMIPS32(Ctx));
   }
 
   void lowerGlobals(std::unique_ptr<VariableDeclarationList> Vars) const final;
@@ -144,6 +149,23 @@
   template <typename T> static void emitConstantPool(GlobalContext *Ctx);
 };
 
+class TargetHeaderMIPS32 final : public TargetHeaderLowering {
+  TargetHeaderMIPS32() = delete;
+  TargetHeaderMIPS32(const TargetHeaderMIPS32 &) = delete;
+  TargetHeaderMIPS32 &operator=(const TargetHeaderMIPS32 &) = delete;
+
+public:
+  static std::unique_ptr<TargetHeaderLowering> create(GlobalContext *Ctx) {
+    return std::unique_ptr<TargetHeaderLowering>(new TargetHeaderMIPS32(Ctx));
+  }
+
+protected:
+  explicit TargetHeaderMIPS32(GlobalContext *Ctx);
+
+private:
+  ~TargetHeaderMIPS32() = default;
+};
+
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGMIPS32_H