Make out arguments non-reference types.

Also, tidy some portable related code.

Change-Id: I67c8aa52eef8b556ca117ecda1b1e75465ba06a5
diff --git a/compiler/llvm/compiler_llvm.cc b/compiler/llvm/compiler_llvm.cc
index a5acd2a..4ce714a 100644
--- a/compiler/llvm/compiler_llvm.cc
+++ b/compiler/llvm/compiler_llvm.cc
@@ -175,16 +175,16 @@
 }  // namespace llvm
 }  // namespace art
 
-inline static art::llvm::CompilerLLVM* ContextOf(art::CompilerDriver& driver) {
+static art::llvm::CompilerLLVM* ContextOf(art::CompilerDriver& driver) {
   void *compiler_context = driver.GetCompilerContext();
   CHECK(compiler_context != NULL);
   return reinterpret_cast<art::llvm::CompilerLLVM*>(compiler_context);
 }
 
-inline static const art::llvm::CompilerLLVM* ContextOf(const art::CompilerDriver& driver) {
+static art::llvm::CompilerLLVM* ContextOf(const art::CompilerDriver& driver) {
   void *compiler_context = driver.GetCompilerContext();
   CHECK(compiler_context != NULL);
-  return reinterpret_cast<const art::llvm::CompilerLLVM*>(compiler_context);
+  return reinterpret_cast<art::llvm::CompilerLLVM*>(compiler_context);
 }
 
 extern "C" void ArtInitCompilerContext(art::CompilerDriver& driver) {
@@ -233,7 +233,7 @@
   return result;
 }
 
-extern "C" void compilerLLVMSetBitcodeFileName(art::CompilerDriver& driver,
-                                               std::string const& filename) {
+extern "C" void compilerLLVMSetBitcodeFileName(const art::CompilerDriver& driver,
+                                               const std::string& filename) {
   ContextOf(driver)->SetBitcodeFileName(filename);
 }
diff --git a/compiler/llvm/compiler_llvm.h b/compiler/llvm/compiler_llvm.h
index 65bc16b..c2211fb 100644
--- a/compiler/llvm/compiler_llvm.h
+++ b/compiler/llvm/compiler_llvm.h
@@ -70,7 +70,7 @@
     return insn_set_;
   }
 
-  void SetBitcodeFileName(std::string const& filename) {
+  void SetBitcodeFileName(const std::string& filename) {
     bitcode_filename_ = filename;
   }
 
diff --git a/compiler/llvm/llvm_compilation_unit.cc b/compiler/llvm/llvm_compilation_unit.cc
index d23706d..1d027f9 100644
--- a/compiler/llvm/llvm_compilation_unit.cc
+++ b/compiler/llvm/llvm_compilation_unit.cc
@@ -199,7 +199,8 @@
   std::string target_triple;
   std::string target_cpu;
   std::string target_attr;
-  CompilerDriver::InstructionSetToLLVMTarget(GetInstructionSet(), target_triple, target_cpu, target_attr);
+  CompilerDriver::InstructionSetToLLVMTarget(GetInstructionSet(), &target_triple, &target_cpu,
+                                             &target_attr);
 
   std::string errmsg;
   const ::llvm::Target* target =