[clang-doc] Add flag to continue after mapping errors

The tool used to stop execution if there was an error in the mapping
phase. It will now show the error but continue with the files that were
mapped correctly if the flag is true.

Differential revision: https://reviews.llvm.org/D65627

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@367729 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed