The Lexer constructor expects a source location at the start of the
file buffer, not at the start of lexing.

Fixes assertion hit in format diagnostics. rdar://11418366

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156647 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed