SI-6546 InnerClasses attribute refers to absent class

At issue is that the optimizer would eliminate closure classes
completely, then neglect to eliminate those classes from the
container's InnerClasses attribute. This breaks tooling which
expects those entries to correspond to real classes.

The code change is essentially mgarcia's - I minimized it and
put the caches in perRunCaches, and added the test case which
verifies that after being compiled under -optimise, there are
no inner classes. Before/after:

  7,8d6
  <   InnerClasses:
  <        public final #22; //class A_1$$anonfun$f$1
  37,45c35,40
  <   #21 = Utf8               A_1$$anonfun$f$1
  <   #22 = Class              #21            //  A_1$$anonfun$f$1
  <   #23 = Utf8               Code
  ---
  >   #21 = Utf8               Code
Fix completion after application with implicit arguments

`List(1, 2, 3).map(f).<ctrl-space>` now works; before
the tree had the type `(bf: CanBuildFrom[...]):...` and
did not contribute completions from the result type.

This commit checks if the tree has an implicit method
type, and typechecks it as a qualifier. That is enough
to get to `adaptToImplicitMethod` in the type checker,
infer the implicit arguments, and compute the final result
type accordingly.
Render relevant properties to buildcharacter.properties
Allow publishing only core (pr validation)
Allow retrieving STARR from non-standard repo for PR validation
Merge pull request #3097 from paulp/issue/6546-for-210

SI-6546 InnerClasses attribute refers to absent class
[backport] SI-7776 post-erasure signature clashes are now macro-aware

"double definition: macro this and method that have same type after erasure"
This error doesn't make sense when macros are involved, because macros
expand at compile-time, where we're not affected by erasure. Moreover,
macros produce no bytecode, which means that we're safe from VerifyErrors.
IDE needs swing/actors/continuations
Merge pull request #3105 from retronym/ticket/completion

Fix completion after application with implicit arguments
Merge pull request #3110 from xeno-by/topic/7776-backport

[backport] SI-7776 post-erasure signature clashes are now macro-aware
Merge pull request #3109 from adriaanm/faster-build-2.10

Faster build 2.10
[backport] Add buildcharacter.properties to .gitignore.

(cherry picked from commit 693e55e1cb75055bb243ffca2e18b8e44e80bb8c)
Merge pull request #3116 from retronym/topic/backport-character-ignore

Add buildcharacter.properties to .gitignore.