* origin/master: (114 commits)
  LEGO: check in for master to temporary branch.
  LEGO: check in for master to temporary branch.
  Enable substitution for object literal shorthand property assignments in the system transform (microsoft#21106)
  Skip outer expressions when checking for super keyword in binder (microsoft#20164)
  Group intersection code in getSimplifiedIndexedAccessType
  Use filter instead of unnecessary laziness
  Remove mapped types to never from intersections
  Handle jsconfig.json in fourslash tests (microsoft#16484)
  Add a `getFullText()` helper method to `IScriptSnapshot` (microsoft#21155)
  Test Diff and Omit
  Keep string index from intersections in base constraint of index type
  LEGO: check in for master to temporary branch.
  Fix bug: get merged symbol of symbol.parent before checking against module symbol (microsoft#21147)
  Do not trigger the failed lookup location invalidation for creation of program emit files Handles microsoft#20934
  Add test where emit of the file results in invalidating resolution and hence invoking recompile
  Parse comment on @Property tag and use as documentation comment (microsoft#21119)
  Update baselines
  push/popTypeResolution for circular base constraints
  LEGO: check in for master to temporary branch.
  Test:incorrect mapped type doesn't infinitely recur
  ...