[clang-format] Add more tests for Objective-C 2.0 generic alignment

[benhamilton]

Summary

In r236412, @djasper added a comment:

// FIXME: We likely want to do this for more combinations of brackets.
// Verify that it is wanted for ObjC, too.

In D42650, @stephanemoore asked me to confirm this.

This followup to D42650 adds more tests to verify the relative
alignment behavior for Objective-C 2.0 generics passed to functions
and removes the second half of the FIXME comment.

Test Plan:

make -j12 FormatTests && \
./tools/clang/unittests/Format/FormatTests --gtest_filter=FormatTestObjC.\*

[stephanemoore]

Looks reasonable 👌

lib/Format/ContinuationIndenter.cpp

if (Current.isOneOf(tok::l_brace, TT_ArrayInitializerLSquare) ||
     NewIndent = Style.ContinuationIndentWidth +
                 std::max(State.Stack.back().LastSpace,
                          State.Stack.back().StartOfFunctionCall);
 
     // Ensure that different different brackets force relative alignment, e.g.:
     // void SomeFunction(vector<  // break
     //                       int> v);
     // FIXME: We likely want to do this for more combinations of brackets.
-    // Verify that it is wanted for ObjC, too.
     if (Current.is(tok::less) && Current.ParentBracket == tok::l_paren) {
       NewIndent = std::max(NewIndent, State.Stack.back().Indent);
       LastSpace = std::max(LastSpace, State.Stack.back().Indent);
     }
 
     bool EndsInComma =
         Current.MatchingParen &&
         Current.MatchingParen->getPreviousNonComment() &&

unittests/Format/FormatTestObjC.cpp

verifyFormat("@autoreleasepool\n"
                "  f();\n"
                "}\n"
                "@autoreleasepool\n"
                "{\n"
                "  f();\n"
                "}\n");
 }
 
+TEST_F(FormatTestObjC, FormatObjCGenerics) {
+  Style.ColumnLimit = 40;
+  verifyFormat("int aaaaaaaaaaaaaaaa(\n"
+               "    NSArray<aaaaaaaaaaaaaaaaaa *>\n"
+               "        aaaaaaaaaaaaaaaaa);\n");
+  verifyFormat("int aaaaaaaaaaaaaaaa(\n"
+               "    NSArray<aaaaaaaaaaaaaaaaaaa<\n"
+               "        aaaaaaaaaaaaaaaa *> *>\n"
+               "        aaaaaaaaaaaaaaaaa);\n");
+}
+
 TEST_F(FormatTestObjC, FormatObjCInterface) {
   verifyFormat("@interface Foo : NSObject <NSSomeDelegate> {\n"
                "@public\n"
                "  int field1;\n"
                "@protected\n"
                "  int field2;\n"
                "@private\n"
                "  int field3;\n"