add method to retrieve host cpu name

add stub method to enginebuilder to setMCPU and setMAttrs -- these are not implemented in llvm3.1

llvm/extra.h

@@ -55,6 +55,8 @@
 extern "C" {
 #endif
 
+const char * LLVMGetHostCPUName();
+
 int LLVMInitializeNativeTargetAsmPrinter();
 
 
@@ -182,6 +184,16 @@ void LLVMEngineBuilderForceInterpreter(LLVMEngineBuilderRef eb);
  */
 void LLVMEngineBuilderSetOptLevel(LLVMEngineBuilderRef eb, int level);
 
+/*
+ * Wraps EngineBuilder::setMCPU
+ */
+void LLVMEngineBuilderSetMCPU(LLVMEngineBuilderRef eb, const char * mcpu);
+
+/*
+ * Wraps EngineBuilder::setMAttrs
+ */
+void LLVMEngineBuilderSetMAttrs(LLVMEngineBuilderRef eb, const char * mattrs);
+
 /*
  * Wraps EngineBuilder::setErrorStr and EngineBuilder::create
  */