[flang] Add dump-symbols option to bbc

Restore the `--dump-symbols` option in the `bbc`
tool.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D129850

flang/test/Semantics/typeinfo01.f90

@@ -1,3 +1,4 @@
+!RUN: bbc --dump-symbols %s | FileCheck %s
 !RUN: %flang_fc1 -fdebug-dump-symbols %s | FileCheck %s
 ! Tests for derived type runtime descriptions
 

flang/tools/bbc/bbc.cpp

@@ -106,6 +106,10 @@ static llvm::cl::opt<bool> warnIsError("Werror",
                                        llvm::cl::desc("warnings are errors"),
                                        llvm::cl::init(false));
 
+static llvm::cl::opt<bool> dumpSymbols("dump-symbols",
+                                       llvm::cl::desc("dump the symbol table"),
+                                       llvm::cl::init(false));
+
 static llvm::cl::opt<bool> pftDumpTest(
     "pft-test",
     llvm::cl::desc("parse the input, create a PFT, dump it, and exit"),
@@ -189,6 +193,11 @@ static mlir::LogicalResult convertFortranSourceToMLIR(
                    << "could not find module file for __fortran_type_info\n";
   }
 
+  if (dumpSymbols) {
+    semantics.DumpSymbols(llvm::outs());
+    return mlir::success();
+  }
+
   if (pftDumpTest) {
     if (auto ast = Fortran::lower::createPFT(parseTree, semanticsContext)) {
       Fortran::lower::dumpPFT(llvm::outs(), *ast);