isLegalUTF8() was giving the wrong answer

invalid but not caught by isLegalUTF8(): 0xED 0x75 0x84

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167063 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed