Extract hardcoded error strings into a single place and replace them with enum.

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index e611c8ae27999a9520d0aa07bfa050b51a0bb831..b07e08c58e4fcd8bd31ff2ba59a5e0e072d4b02d 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -1002,7 +1002,7 @@ class MacroAssembler: public Assembler {
   // enabled via --debug-code.
   void AssertRootValue(Register src,
                        Heap::RootListIndex root_value_index,
-                       const char* message);
+                       BailoutReason reason);
 
   // ---------------------------------------------------------------------------
   // Exception handling
@@ -1319,15 +1319,15 @@ class MacroAssembler: public Assembler {
 
   // Calls Abort(msg) if the condition cc is not satisfied.
   // Use --debug_code to enable.
-  void Assert(Condition cc, const char* msg);
+  void Assert(Condition cc, BailoutReason reason);
 
   void AssertFastElements(Register elements);
 
   // Like Assert(), but always enabled.
-  void Check(Condition cc, const char* msg);
+  void Check(Condition cc, BailoutReason reason);
 
   // Print a message to stdout and abort execution.
-  void Abort(const char* msg);
+  void Abort(BailoutReason msg);
 
   // Check that the stack is aligned.
   void CheckStackAlignment();