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

[benhamilton]

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

lib/Format/TokenAnnotator.cpp

case tok::colon:
       } else if (Contexts.size() == 1 &&
                  !Line.First->isOneOf(tok::kw_enum, tok::kw_case)) {
         if (Tok->getPreviousNonComment()->isOneOf(tok::r_paren,
                                                   tok::kw_noexcept))
           Tok->Type = TT_CtorInitializerColon;
         else
           Tok->Type = TT_InheritanceColon;
       } else if (Tok->Previous->is(tok::identifier) && Tok->Next &&
-                 Tok->Next->isOneOf(tok::r_paren, tok::comma)) {
+                 (Tok->Next->isOneOf(tok::r_paren, tok::comma) ||
+                  Tok->Next->startsSequence(tok::identifier, tok::colon))) {
         // This handles a special macro in ObjC code where selectors including
         // the colon are passed as macro arguments.
         Tok->Type = TT_ObjCMethodExpr;
       } else if (Contexts.back().ContextKind == tok::l_paren) {
         Tok->Type = TT_InlineASMColon;
       }
       break;
     case tok::pipe:

unittests/Format/FormatTestObjC.cpp

TEST_F(FormatTestObjC, FormatObjCMethodExpr) {
   verifyFormat("for (int i = 0; i < in[a]; ++i) {\n}");
   verifyFormat("for (int i = 0; in[a] < i; ++i) {\n}");
   verifyFormat("for (int i = 0; i < n; ++i, ++in[a]) {\n}");
   verifyFormat("for (int i = 0; i < n; ++i, in[a]++) {\n}");
   verifyFormat("for (int i = 0; i < f(in[a]); ++i, in[a]++) {\n}");
   verifyFormat("for (id foo in [self getStuffFor:bla]) {\n"
                "}");
   verifyFormat("[self aaaaa:MACRO(a, b:, c:)];");
+  verifyFormat("[self aaaaa:MACRO(a, b:c:, d:e:)];");
+  verifyFormat("[self aaaaa:MACRO(a, b:c:d:, e:f:g:)];");
+  verifyFormat("int XYMyFoo(int a, int b) NS_SWIFT_NAME(foo(self:scale:));");
   verifyFormat("[self aaaaa:(1 + 2) bbbbb:3];");
   verifyFormat("[self aaaaa:(Type)a bbbbb:3];");
 
   verifyFormat("[self stuffWithInt:(4 + 2) float:4.5];");
   verifyFormat("[self stuffWithInt:a ? b : c float:4.5];");
   verifyFormat("[self stuffWithInt:a ? [self foo:bar] : c];");
   verifyFormat("[self stuffWithInt:a ? (e ? f : g) : c];");
   verifyFormat("[cond ? obj1 : obj2 methodWithParam:param]");