[turbofan] Add support for relevant ES6 type conversion intrinsics.

src/type-cache.h

Index: src/type-cache.h
diff --git a/src/type-cache.h b/src/type-cache.h
index 2b04c247cb8864a5a9ee777dc4a48ef70e6a813c..f55198f8899be87c322621820c3fa72e3d900361 100644
--- a/src/type-cache.h
+++ b/src/type-cache.h
@@ -46,7 +46,11 @@ class TypeCache final {
   Type* const kZeroish =
       Type::Union(kSingletonZero, Type::MinusZeroOrNaN(), zone());
   Type* const kInteger = CreateRange(-V8_INFINITY, V8_INFINITY);
-  Type* const kWeakint = Type::Union(kInteger, Type::MinusZeroOrNaN(), zone());
+  Type* const kPositiveInteger = CreateRange(0.0, V8_INFINITY);
+  Type* const kIntegerish = Type::Union(kInteger, Type::MinusZero(), zone());

[Jarin, 2015/11/05 09:25:29]

I think we need better names for this. How about kIntegerOrMinusZero,
kIntegerOrMinusZeroOrNaN or some such?

Especially because this is inconsistent with the Zeroish above, where the -ish
meand -or-minus-zero-or-nan. (So by your new scheme it would be WeakZero?)

[Benedikt Meurer, 2015/11/05 09:30:05]

Done.

+  Type* const kWeakint = Type::Union(kIntegerish, Type::NaN(), zone());
+
+  Type* const kPositiveSafeInteger = CreateRange(0.0, kMaxSafeInteger);
 
   Type* const kIntegral32 = Type::Union(kInt32, kUint32, zone());