[opt] Pin region viewer passes to legacy PM.

The RegionPrinter, RegionOnlyPrinter, RegionViewer and RegionOnlyViewer passes have not yet been ported to the new pass manager.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D119897

Author: Meinersbur

llvm/tools/opt/opt.cpp

@@ -499,7 +499,9 @@ static bool shouldPinPassToLegacyPM(StringRef Pass) {
       "loop-reduce",          "lower-amx-type",
       "pre-amx-config",       "lower-amx-intrinsics",
       "polyhedral-info",      "replace-with-veclib",
-      "jmc-instrument"};
+      "jmc-instrument",       "dot-regions",
+      "dot-regions-only",     "view-regions",
+      "view-regions-only"};
   for (const auto &P : PassNamePrefix)
     if (Pass.startswith(P))
       return true;