includes: Make ast.h not need isolate.h any more.

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index cce143a38d3841189ff19cf3510b1edd8409f0f1..e914e814de0a37c99baa4b0d0952b2bac96ca244 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -436,7 +436,7 @@ AstGraphBuilder::AstGraphBuilder(Zone* local_zone, CompilationInfo* info,
       frame_state_function_info_(common()->CreateFrameStateFunctionInfo(
           FrameStateType::kJavaScriptFunction, info->num_parameters() + 1,
           info->scope()->num_stack_slots(), info->shared_info())) {
-  InitializeAstVisitor(info->isolate());
+  InitializeAstVisitor(info->isolate()->stack_guard()->real_climit());
 }