[COFF] Initalize ErrorHandler with CanExitEarly value

Previously, the COFF driver would call exit(1) from the
ErrorHandler in the case of a link error, even if
CanExitEarly=false was specified. Now it initializes
the ErrorHandler in the same way that the ELF driver does.

Patch by Andrew Kelley.

Differential Revision: https://reviews.llvm.org/D41803

llvm-svn: 321983

lld/COFF/Driver.cpp

@@ -57,6 +57,7 @@ bool link(ArrayRef<const char *> Args, bool CanExitEarly, raw_ostream &Diag) {
   errorHandler().ErrorLimitExceededMsg =
       "too many errors emitted, stopping now"
       " (use /ERRORLIMIT:0 to see all errors)";
+  errorHandler().ExitEarly = CanExitEarly;
   Config = make<Configuration>();
   Config->Argv = {Args.begin(), Args.end()};
   Config->CanExitEarly = CanExitEarly;