clang-format: Fix WebKit BeforeElse brace wrapping style

[cjk]

Summary

Per https://webkit.org/code-style-guidelines/#linebreaking-else-braces,
WebKit style is for braces to be on the same line as the else.

[cjk]

@djasper: Tagged you because it seems like you've reviewed a bunch of recent clang-format patches. This is my first patch to any of the projects in the LLVM family, so please let me know if I've done something stupid, not added the proper reviewers/lists, etc.

Cheers!

[djasper]

Looks good. Funny that we don't seem to have a test for this.

[cjk]

Excellent. Mind committing this on my behalf? I don't have commit access.

[djasper]

Submitted as r255484.

lib/Format/Format.cpp

case FormatStyle::BS_Allman:
     Expanded.BraceWrapping.BeforeElse = true;
     break;
   case FormatStyle::BS_GNU:
     Expanded.BraceWrapping = {true, true, true, true, true, true,
                               true, true, true, true, true};
     break;
   case FormatStyle::BS_WebKit:
     Expanded.BraceWrapping.AfterFunction = true;
-    Expanded.BraceWrapping.BeforeElse = true;
     break;
   default:
     break;
   }
   return Expanded;
 }
 
 FormatStyle getLLVMStyle() {