Begin a more aggressive refactoring of the Compiler interface.

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
diff --git a/src/x64/codegen-x64.cc b/src/x64/codegen-x64.cc
index ea5a8818af20d79cb88bbcca3269cb05b1946080..28cc205c106f7f5d61cebe2b2acc59bc3c112f72 100644
--- a/src/x64/codegen-x64.cc
+++ b/src/x64/codegen-x64.cc
@@ -178,7 +178,7 @@ void CodeGenerator::Generate(CompilationInfo* info) {
 
   // Adjust for function-level loop nesting.
   ASSERT_EQ(0, loop_nesting_);
-  loop_nesting_ = info->loop_nesting();
+  loop_nesting_ = info->is_in_loop() ? 1 : 0;
 
   JumpTarget::set_compiling_deferred_code(false);
 
@@ -356,7 +356,7 @@ void CodeGenerator::Generate(CompilationInfo* info) {
   }
 
   // Adjust for function-level loop nesting.
-  ASSERT_EQ(loop_nesting_, info->loop_nesting());
+  ASSERT_EQ(loop_nesting_, info->is_in_loop() ? 1 : 0);
   loop_nesting_ = 0;
 
   // Code generation state must be reset.