[flang] Dump parse tree even if semantic error occurs

When -fdebug-dump-parse-tree is specified, dump the parse tree even
if semantic errors have occurred. This is necessary to see the parse
tree after it has been transformed.

Original-commit: flang-compiler/f18@bbdb0717da
Reviewed-on: https://github.com/flang-compiler/f18/pull/417

flang/tools/f18/f18.cc

@@ -232,6 +232,9 @@ std::string CompileFortran(std::string path, Fortran::parser::Options options,
     if (semantics.AnyFatalError()) {
       std::cerr << driver.prefix << "semantic errors in " << path << '\n';
       exitStatus = EXIT_FAILURE;
+      if (driver.dumpParseTree) {
+        Fortran::parser::DumpTree(std::cout, parseTree);
+      }
       return {};
     }
     if (driver.dumpUnparseWithSymbols) {