Fix AstGraphBuilder for loops like for(;;).

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/640203004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24777 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/ast-graph-builder.cc

@@ -610,6 +610,8 @@ void AstGraphBuilder::VisitForStatement(ForStatement* stmt) {
     VisitForTest(stmt->cond());
     Node* condition = environment()->Pop();
     for_loop.BreakUnless(condition);
+  } else {
+    for_loop.BreakUnless(jsgraph()->TrueConstant());
   }
   VisitIterationBody(stmt, &for_loop, 0);
   for_loop.EndBody();

test/cctest/cctest.status

@@ -150,9 +150,6 @@
   'test-debug/DebugEventContext': [PASS, NO_VARIANTS],
   'test-debug/DebugBreakInline': [PASS, NO_VARIANTS],
 
-  # Scheduling and verifying of empty for loops is broken.
-  'test-run-jsbranches/EmptyFor': [SKIP],
-
   ############################################################################
   # Slow tests.
   'test-api/Threading1': [PASS, ['mode == debug', SLOW]],

test/mjsunit/mjsunit.status

@@ -120,9 +120,6 @@
   'regress/regress-crbug-259300': [PASS, NO_VARIANTS],
   'regress/regress-frame-details-null-receiver': [PASS, NO_VARIANTS],
 
-  # Infinite loops of the form "for(;;) ;" don't schedule or crash in verifier.
-  'asm/infinite-loops': [PASS, NO_VARIANTS],
-
   ##############################################################################
   # Too slow in debug mode with --stress-opt mode.
   'compiler/regress-stacktrace-methods': [PASS, ['mode == debug', SKIP]],