Don't use PrintFatalError(which calls exit) for 'Primary decode conflict'. Just skip emitting the table. This way the main function will delete the output file instead of it remaining empty and confusing dependency checks if build is invoked a second time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198529 91177308-0d34-0410-b5e6-96231b3b80d8