[x86] Faster/shorter code for stack checks.

src/compiler/node-matchers.h

Index: src/compiler/node-matchers.h
diff --git a/src/compiler/node-matchers.h b/src/compiler/node-matchers.h
index 1a29bb830e194c9d813b122eb2a0f12367a29f95..48ff3d732326406a04289afddd8a4ce004cf19fc 100644
--- a/src/compiler/node-matchers.h
+++ b/src/compiler/node-matchers.h
@@ -7,6 +7,8 @@
 
 #include <cmath>
 
+// TODO(turbofan): Move ExternalReference out of assembler.h
+#include "src/assembler.h"
 #include "src/compiler/node.h"
 #include "src/compiler/operator.h"
 #include "src/unique.h"
@@ -155,6 +157,32 @@ struct HeapObjectMatcher FINAL
 };
 
 
+// A pattern matcher for external reference constants.
+struct ExternalReferenceMatcher FINAL
+    : public ValueMatcher<ExternalReference, IrOpcode::kExternalConstant> {
+  explicit ExternalReferenceMatcher(Node* node)
+      : ValueMatcher<ExternalReference, IrOpcode::kExternalConstant>(node) {}
+};
+
+
+// For shorter pattern matching code, this struct matches the inputs to
+// machine-level load operations.
+template <typename Object>
+struct LoadMatcher : public NodeMatcher {
+  explicit LoadMatcher(Node* node)
+      : NodeMatcher(node), object_(InputAt(0)), index_(InputAt(1)) {}
+
+  typedef Object ObjectMatcher;
+
+  Object const& object() const { return object_; }
+  IntPtrMatcher const& index() const { return index_; }
+
+ private:
+  Object const object_;
+  IntPtrMatcher const index_;
+};
+
+
 // For shorter pattern matching code, this struct matches both the left and
 // right hand sides of a binary operation and can put constants on the right
 // if they appear on the left hand side of a commutative operation.