Allow setting breakpoints in function literal field initializers under --dfe.

runtime/vm/kernel_to_il.cc

Index: runtime/vm/kernel_to_il.cc
diff --git a/runtime/vm/kernel_to_il.cc b/runtime/vm/kernel_to_il.cc
index 4ada7539e9aa809197f4222a06d763f7ebde1227..82508b1fca96427e4c83d180bd2f0bc6cd277eb5 100644
--- a/runtime/vm/kernel_to_il.cc
+++ b/runtime/vm/kernel_to_il.cc
@@ -76,6 +76,18 @@ TranslationHelper::TranslationHelper(Thread* thread)
       string_data_(TypedData::Handle(Z)),
       canonical_names_(TypedData::Handle(Z)) {}
 
+TranslationHelper::TranslationHelper(Thread* thread,
+                                     dart::RawTypedData* string_offsets,
+                                     dart::RawTypedData* string_data,
+                                     dart::RawTypedData* canonical_names)
+    : thread_(thread),
+      zone_(thread->zone()),
+      isolate_(thread->isolate()),
+      allocation_space_(thread->IsMutatorThread() ? Heap::kNew : Heap::kOld),

[siva, 2017/07/17 22:39:23]

When does this constructor run on a non Mutator thread?

[sivachandra, 2017/07/17 23:49:36]

Per my limited knowledge, the use case added by this change does not run on a
non-mutator thread. However, I just copied this part from the above constructor
to be consistent.

[siva, 2017/07/18 22:49:06]

True but that was because this code could be executed by the background
compiler, but in your case we should not be ever executing it from anything but
the mutator thread, maybe you could add and assert in the constructor
ASSERT(thread->IsMutatorThread());

[sivachandra, 2017/07/19 00:14:21]

Done.

+      string_offsets_(TypedData::Handle(Z, string_offsets)),
+      string_data_(TypedData::Handle(Z, string_data)),
+      canonical_names_(TypedData::Handle(Z, canonical_names)) {}
+
 void TranslationHelper::SetStringOffsets(const TypedData& string_offsets) {
   ASSERT(string_offsets_.IsNull());
   string_offsets_ = string_offsets.raw();