Make rewriter::inserttext return a bool to indicate if it failed.

Add a RewriteTest::ReplaceStmt method to factor the 'checking for
rewrite failed + emitting diagnostic if so' code.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@46619 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed