[clang-format] Fix ObjC selectors with multiple params passed to macro

[clang-format] Fix ObjC selectors with multiple params passed to macro

Summary:
Objective-C selectors with arguments take the form of:

foo:
foo:bar:
foo:bar:baz:

These can be passed to a macro, like NS_SWIFT_NAME():

https://developer.apple.com/library/content/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html

and must never have spaces inserted around the colons.

Previously, there was logic in TokenAnnotator's tok::colon parser to
handle the single-argument case, but it failed for the
multiple-argument cases.

This diff fixes the bug and adds more tests.

Test Plan: New tests added. Ran tests with:
  % make -j12 FormatTests && ./tools/clang/unittests/Format/FormatTests

Reviewers: jolesiak, djasper, Wizard

Reviewed By: jolesiak, Wizard

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D44638

llvm-svn: 327986