[turbofan] Work towards fixing asm.js heap access.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 3e9d3d98ec225da03a62771a0f5dc106d1a6f455..e63c433214c002089fb21b59fbf4d4f1df22d297 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -1669,11 +1669,6 @@ Bounds Typer::Visitor::TypeNumberToUint32(Node* node) {
 }
 
 
-Bounds Typer::Visitor::TypePlainPrimitiveToNumber(Node* node) {
-  return TypeUnaryOp(node, ToNumber);
-}
-
-
 Bounds Typer::Visitor::TypeReferenceEqual(Node* node) {
   return Bounds(Type::None(zone()), Type::Boolean(zone()));
 }
@@ -1794,8 +1789,6 @@ Bounds Typer::Visitor::TypeLoadField(Node* node) {
 
 
 Bounds Typer::Visitor::TypeLoadBuffer(Node* node) {
-  // TODO(bmeurer): This typing is not yet correct. Since we can still access
-  // out of bounds, the type in the general case has to include Undefined.
   switch (BufferAccessOf(node->op()).external_array_type()) {
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \
   case kExternal##Type##Array:                          \