Code cleanup to avoid LLVM dependency when building with quick only.

Change-Id: I0985c227d775c72fd23975d4c9bf673ba32615c2
diff --git a/compiler/dex/compiler_ir.h b/compiler/dex/compiler_ir.h
index ded8005..8447d23 100644
--- a/compiler/dex/compiler_ir.h
+++ b/compiler/dex/compiler_ir.h
@@ -18,25 +18,18 @@
 #define ART_COMPILER_DEX_COMPILER_IR_H_
 
 #include <vector>
-#include <llvm/IR/Module.h>
+
 #include "compiler_enums.h"
 #include "dex/quick/mir_to_lir.h"
 #include "dex_instruction.h"
 #include "driver/compiler_driver.h"
 #include "driver/dex_compilation_unit.h"
-#include "llvm/intrinsic_helper.h"
-#include "llvm/ir_builder.h"
 #include "safe_map.h"
 #include "base/timing_logger.h"
 #include "utils/arena_allocator.h"
 
 namespace art {
 
-class LLVMInfo;
-namespace llvm {
-class LlvmCompilationUnit;
-}  // namespace llvm
-
 struct ArenaMemBlock;
 class Backend;
 struct Memstats;