implement the null function for the Mips32 subzero compiler

src/IceAssemblerMIPS32.h

Index: src/IceAssemblerMIPS32.h
diff --git a/src/assembler_mips32.h b/src/IceAssemblerMIPS32.h
similarity index 92%
rename from src/assembler_mips32.h
rename to src/IceAssemblerMIPS32.h
index b5bca57210104f5cdff50eedcafdbceb03cf8dc6..15b2d6b21a942e565e80f4b34f55a89b5c167993 100644
--- a/src/assembler_mips32.h
+++ b/src/IceAssemblerMIPS32.h
@@ -47,10 +47,12 @@ public:
 
   SizeT getBundleAlignLog2Bytes() const override { return 4; }
 
-  const char *getNonExecPadDirective() const override { return ".TBD"; }
+  const char *getNonExecPadDirective() const override { return ".p2alignl"; }
 
   llvm::ArrayRef<uint8_t> getNonExecBundlePadding() const override {
-    llvm::report_fatal_error("Not yet implemented.");
+    // TBD (Reed Kotler ) . Find out what this should be.

[jvoung (off chromium), 2015/06/12 19:39:12]

nit: Usually we try to format the "TODO"s consistently as TODO(username), so
that it's easier to grep for.

E.g., you have TODO(reed kotler) in some other places.

+    static const uint8_t Padding[] = {0xE7, 0xFE, 0xDE, 0xF0};
+    return llvm::ArrayRef<uint8_t>(Padding, 4);
   }
 
   void padWithNop(intptr_t Padding) override {