Fix bug in clang-format while merging short function

Before:
    #ifdef _DEBUG
    int foo( int i = 0 )
    #else
    int foo( int i = 5 )
    #endif { return i; }

After:
    #ifdef _DEBUG
    int foo( int i = 0 )
    #else
    int foo( int i = 5 )
    #endif
    {
    	return i;
    }



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207958 91177308-0d34-0410-b5e6-96231b3b80d8