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

src/ast/ast-expression-rewriter.h

Index: src/ast/ast-expression-rewriter.h
diff --git a/src/ast/ast-expression-rewriter.h b/src/ast/ast-expression-rewriter.h
index 304aa1241c07d88d256a20238a8953f01a1132c7..ac45d76b30688a1e27e5c5d51ac983174770d372 100644
--- a/src/ast/ast-expression-rewriter.h
+++ b/src/ast/ast-expression-rewriter.h
@@ -21,6 +21,9 @@
 // methods so they can be specialized by subclasses.
 class AstExpressionRewriter : public AstVisitor<AstExpressionRewriter> {
  public:
+  explicit AstExpressionRewriter(Isolate* isolate) {
+    InitializeAstRewriter(isolate);
+  }
   explicit AstExpressionRewriter(uintptr_t stack_limit) {
     InitializeAstRewriter(stack_limit);
   }