[clang-format] Fix support for ObjC blocks with pointer return types

[jaredgrubb]

Summary

The ObjC-block detection code only supports a single token as the return type. Add support to detect pointers, too (ObjC has lots of object-pointers).

For example, using BasedOnStyle: WebKit, the following is stable output:

int* p = ^int*(void)
{ //
    return nullptr;
}
();

After the patch:

int* p = ^int*(void) { //
    return nullptr;
}();

[MyDeveloperDay]

clang/unittests/Format/FormatTest.cpp

22178

I don’t like us changing tests

[jaredgrubb]

clang/unittests/Format/FormatTest.cpp

22178

Normally I would agree, but in this case, this is a bug-fix for the test as well.

If you look at the verifyFormat just below this one, its braces are broken across separate lines. The inconsistency between these two tests was due to the difference in the block's return type (pointer vs non-pointer).

My patch corrects exactly that inconsistency.

[MyDeveloperDay]

LGTM

[owenpan]

clang/lib/Format/UnwrappedLineParser.cpp

1779–1782

clang/unittests/Format/FormatTestObjC.cpp

1007–1010