[turbofan] Introduce a Function type and optimize based on it.

src/types.h

Index: src/types.h
diff --git a/src/types.h b/src/types.h
index fb4e580491a12dd95c58f95e9e34cab41e1f7004..3c9e8c29226116b55930a4da25cbb73d19e4cb69 100644
--- a/src/types.h
+++ b/src/types.h
@@ -159,8 +159,8 @@ namespace internal {
 // clang-format off
 
 #define MASK_BITSET_TYPE_LIST(V) \
-  V(Representation, 0xfff00000u) \
-  V(Semantic,       0x000ffffeu)
+  V(Representation, 0xff800000u) \
+  V(Semantic,       0x007ffffeu)
 
 #define REPRESENTATION(k) ((k) & BitsetType::kRepresentation)
 #define SEMANTIC(k)       ((k) & BitsetType::kSemantic)
@@ -205,7 +205,8 @@ namespace internal {
   V(Undetectable,        1u << 16 | REPRESENTATION(kTaggedPointer)) \
   V(OtherObject,         1u << 17 | REPRESENTATION(kTaggedPointer)) \
   V(Proxy,               1u << 18 | REPRESENTATION(kTaggedPointer)) \
-  V(Internal,            1u << 19 | REPRESENTATION(kTagged | kUntagged)) \
+  V(Function,            1u << 19 | REPRESENTATION(kTaggedPointer)) \
+  V(Internal,            1u << 20 | REPRESENTATION(kTagged | kUntagged)) \
   \
   V(Signed31,            kUnsigned30 | kNegative31) \
   V(Signed32,            kSigned31 | kOtherUnsigned31 | kOtherSigned32) \
@@ -226,11 +227,10 @@ namespace internal {
   V(NumberOrUndefined,   kNumber | kUndefined) \
   V(PlainPrimitive,      kNumberOrString | kBoolean | kNullOrUndefined) \
   V(Primitive,           kSymbol | kSimd | kPlainPrimitive) \
-  V(DetectableReceiver,  kOtherObject | kProxy) \
+  V(DetectableReceiver,  kFunction | kOtherObject | kProxy) \
   V(Detectable,          kDetectableReceiver | kNumber | kName) \
-  V(Object,              kOtherObject | kUndetectable) \
+  V(Object,              kFunction | kOtherObject | kUndetectable) \
   V(Receiver,            kObject | kProxy) \
-  V(ReceiverOrUndefined, kReceiver | kUndefined) \
   V(StringOrReceiver,    kString | kReceiver) \
   V(Unique,              kBoolean | kUniqueName | kNull | kUndefined | \
                          kReceiver) \