* Pre-Dart SDK roll engine revision

* Dart SDK engine roll for 2018-05-30.

Commits:

3b6caa3517b Split UnresolvedNameGenerator
f50873d3451 [fuchsia] Renaming component FIDL to fuchsia.sys.
13987b073d6 Add Forest method to access the name of a variable
declaration
3b86f823d0a [vm/corelib] Remove GrowableArrayMarker hack.
88127f10e4f Clean up num#toStringAsPrecision docs
1eb1885c62d tools/addlatexhash.dart: Remove unused import
03cb46a2290 [vm/perf] Fix JITDUMP integration.
9d9eff44c99 Support sharing function signatures in deferred parts for
fast startup
ae9f5d2a1b1 Add Forest API for logical expressions
66c590d3ad3 Add json/utf8 BOM support in changelog.
d116e62d76d Improve catch parameter recovery
aa8e2ee178d Revert "[vm] Add tests for determinism of script and AppJIT
snapshots."
ec47e524bc9 Switch to non-alpha versions for analyzer/front_end/kernel.
aac0478fada [vm] Add tests for determinism of script and AppJIT
snapshots.
6cc7aa803a1 Change names/declarations tasks in AnalysisDriver sync.
c30af41b96c Reapply "[mirrors] Add IsolateMirror.loadUri."
a40993a6aff Observatory strong mode fix: Fix incorrect types in
DebuggerStackElement.
0fdfc9aa3b6 Observatory strong mode fix: Add a needed implements clause.
209029ab8ee Observatory strong mode fix: Pass through a type parameter
in the implements clause for GuardedMock.
1d323687b39 Use selection to decide whether EXTRACT_LOCAL_VARIABLE and
EXTRACT_METHOD are available.