[turbofan] Introduce initial support for TypedArrays.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 316a4090cfc74b00b5bfbd953b283bc6c26796e4..aa3e038d8e046e80d5bd1974d99a70288fe08c98 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -1975,6 +1975,17 @@ Type* Typer::Visitor::TypeLoadElement(Node* node) {
   return ElementAccessOf(node->op()).type;
 }
 
+Type* Typer::Visitor::TypeLoadTypedElement(Node* node) {
+  switch (ExternalArrayTypeOf(node->op())) {
+#define TYPED_ARRAY_CASE(ElemType, type, TYPE, ctype, size) \
+  case kExternal##ElemType##Array:                          \
+    return typer_->cache_.k##ElemType;
+    TYPED_ARRAYS(TYPED_ARRAY_CASE)
+#undef TYPED_ARRAY_CASE
+  }
+  UNREACHABLE();
+  return nullptr;
+}
 
 Type* Typer::Visitor::TypeStoreField(Node* node) {
   UNREACHABLE();
@@ -1993,6 +2004,11 @@ Type* Typer::Visitor::TypeStoreElement(Node* node) {
   return nullptr;
 }
 
+Type* Typer::Visitor::TypeStoreTypedElement(Node* node) {
+  UNREACHABLE();
+  return nullptr;
+}
+
 Type* Typer::Visitor::TypeObjectIsCallable(Node* node) {
   return TypeUnaryOp(node, ObjectIsCallable);
 }
@@ -2026,6 +2042,13 @@ Type* Typer::Visitor::TypeDebugBreak(Node* node) { return Type::None(); }
 
 Type* Typer::Visitor::TypeComment(Node* node) { return Type::None(); }
 
+Type* Typer::Visitor::TypeRetain(Node* node) {
+  UNREACHABLE();
+  return nullptr;
+}
+
+Type* Typer::Visitor::TypeUnsafePointerAdd(Node* node) { return Type::None(); }
+
 Type* Typer::Visitor::TypeLoad(Node* node) { return Type::Any(); }
 
 Type* Typer::Visitor::TypeStackSlot(Node* node) { return Type::Any(); }