Use entities as keys rather than IR nodes

pkg/compiler/lib/src/kernel/element_map.dart

Index: pkg/compiler/lib/src/kernel/element_map.dart
diff --git a/pkg/compiler/lib/src/kernel/element_map.dart b/pkg/compiler/lib/src/kernel/element_map.dart
index 49ba84766bf1fbb4db0287c576c675dadd9afcbf..2b2c3c6f004f6233486433b0205d400a9b71fae8 100644
--- a/pkg/compiler/lib/src/kernel/element_map.dart
+++ b/pkg/compiler/lib/src/kernel/element_map.dart
@@ -155,6 +155,14 @@ abstract class KernelToElementMap {
   /// Returns a [Spannable] for a message pointing to the IR [node] in the
   /// context of [member].
   Spannable getSpannable(MemberEntity member, ir.Node node);
+
+  // TODO(johnniwinther): Move these to a `KernelToLocalsMap`, maybe even make
+  // the return the `KernelToLocalsMap` to use from now on.
+  /// Call to notify that [member] is currently being inlined.
+  void enterInlinedMember(MemberEntity member);

[Siggi Cherem (dart-lang), 2017/06/01 22:08:47]

mmm. Maybe you have more in mind behind this, but it seems odd to me to add this
on this interface. I had the impression this interface was pretty much
stateless.

In this case, it feels like this inlining stack is mainly used for the ssa
builder, so I'd be inclined to keep it contained there.

[Siggi Cherem (dart-lang), 2017/06/01 22:15:39]

ha - just saw the next CL, seems like we are in agreement here.

If it is easy to remove it from this API and only keep it in the ast adapter,
then that might be a cleaner intermediate thing to land

+
+  /// Call to notify that [member] is no longer being inlined.
+  void leaveInlinedMember(MemberEntity member);
 }
 
 /// Kinds of foreign functions.
@@ -509,6 +517,12 @@ abstract class KernelToElementMapMixin implements KernelToElementMap {
         message: "No super noSuchMethod found for class $cls."));
     return function;
   }
+
+  @override
+  void enterInlinedMember(MemberEntity member) {}
+
+  @override
+  void leaveInlinedMember(MemberEntity member) {}
 }
 
 /// Visitor that converts string literals and concatenations of string literals
@@ -920,6 +934,10 @@ abstract class KernelToTypeInferenceMap {
   bool isJsIndexableIterator(
       ir.ForInStatement forInStatement, ClosedWorld closedWorld);
 
+  /// Returns `true` if [mask] is inferred to have a JavaScript `length`
+  /// property.
+  bool isFixedLength(TypeMask mask, ClosedWorld closedWorld);
+
   /// Returns the inferred index type of [forInStatement].
   TypeMask inferredIndexType(ir.ForInStatement forInStatement);