Merged r16012, r16014, r16037, r16042, r16082, r16085, r16101, r16102, r16106 into trunk branch.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index f84c357fddb885209679735801ba471cf0eced2e..c2207317c185e501689a57dfbc8dac97c09a9891 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -1999,6 +1999,12 @@ void LCodeGen::DoBranch(LBranch* instr) {
         __ bind(&not_string);
       }
 
+      if (expected.Contains(ToBooleanStub::SYMBOL)) {
+        // Symbol value -> true.
+        __ CmpInstanceType(map, SYMBOL_TYPE);
+        __ j(equal, instr->TrueLabel(chunk_));
+      }
+
       if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
         // heap number -> false iff +0, -0, or NaN.
         Label not_heap_number;