Remove obsolete isolate from CompareOperation predicate.

src/ast/ast.h

Index: src/ast/ast.h
diff --git a/src/ast/ast.h b/src/ast/ast.h
index 7127104f09cdf5e2424a7f6af4e74e513942fa7c..539a848370a22f39b11dd13467f34c8308183c65 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -330,8 +330,9 @@ class Expression : public AstNode {
   // True iff the expression is the null literal.
   bool IsNullLiteral() const;
 
-  // True if we can prove that the expression is the undefined literal.
-  bool IsUndefinedLiteral(Isolate* isolate) const;
+  // True if we can prove that the expression is the undefined literal. Note
+  // that this also checks for loads of the global "undefined" variable.
+  bool IsUndefinedLiteral() const;
 
   // True iff the expression is a valid target for an assignment.
   bool IsValidReferenceExpressionOrThis() const;
@@ -2285,7 +2286,7 @@ class CompareOperation final : public Expression {
 
   // Match special cases.
   bool IsLiteralCompareTypeof(Expression** expr, Handle<String>* check);
-  bool IsLiteralCompareUndefined(Expression** expr, Isolate* isolate);
+  bool IsLiteralCompareUndefined(Expression** expr);
   bool IsLiteralCompareNull(Expression** expr);
 
  protected: