[clang-format/ObjC] Do not insert space after opening brace of ObjC dict literal

[benhamilton]

Summary

D44816 attempted to fix a few cases where clang-format incorrectly
inserted a space before the closing brace of an Objective-C dictionary
literal.

This revealed there were still a few cases where we inserted a space
after the opening brace of an Objective-C dictionary literal.

This fixes the formatting to be consistent and adds more tests.

Test Plan: New tests added. Confirmed tests failed before

diff and passed after diff.
Ran tests with:
% make -j12 FormatTests && ./tools/clang/unittests/Format/FormatTests

[djasper]

Looks good.

lib/Format/TokenAnnotator.cpp

if (Right.is(tok::hash) && Left.is(tok::identifier) && Left.TokenText == "L")
     return false;
   if (Left.is(TT_TemplateCloser) && Left.MatchingParen &&
       Left.MatchingParen->Previous &&
       Left.MatchingParen->Previous->is(tok::period))
     // A.<B<C<...>>>DoSomething();
     return false;
   if (Left.is(TT_TemplateCloser) && Right.is(tok::l_square))
     return false;
+  if (Left.is(tok::l_brace) && Left.endsSequence(TT_DictLiteral, tok::at))
+    // Objective-C dictionary literal -> no space after opening brace.
+    return false;
   if (Right.is(tok::r_brace) && Right.MatchingParen &&
       Right.MatchingParen->endsSequence(TT_DictLiteral, tok::at))
     // Objective-C dictionary literal -> no space before closing brace.
     return false;
   return true;
 }
 
 bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,

unittests/Format/FormatTestObjC.cpp

verifyFormat(
       "  (aaaaaaaa id)aaaaaaaaa : (aaaaaaaa id)aaaaaaaaaaaaaaaaaaaaaaaa,\n"
       "  (aaaaaaaa id)aaaaaaaaaaaaaa : (aaaaaaaa id)aaaaaaaaaaaaaa,\n"
       "};");
   Style.ColumnLimit = 40;
   verifyFormat("int Foo() {\n"
                "  a12345 = @{a12345 : a12345};\n"
                "}");
   verifyFormat("int Foo() {\n"
+               "  a12345 = @{a12345 : @(a12345)};\n"
+               "}");
+  verifyFormat("int Foo() {\n"
                "  a12345 = @{(Foo *)a12345 : @(a12345)};\n"
                "}");
+  verifyFormat("int Foo() {\n"
+               "  a12345 = @{@(a12345) : a12345};\n"
+               "}");
+  verifyFormat("int Foo() {\n"
+               "  a12345 = @{@(a12345) : @YES};\n"
+               "}");
   Style.SpacesInContainerLiterals = false;
   verifyFormat("int Foo() {\n"
                "  b12345 = @{b12345: b12345};\n"
                "}");
   verifyFormat("int Foo() {\n"
                "  b12345 = @{(Foo *)b12345: @(b12345)};\n"
                "}");
   Style.SpacesInContainerLiterals = true;