[nim-gdb] Fixed enums and flag output [ci skip] (#17634)

Debugger works for enums again. Additionally, flags work better than before.

Reworked object printer as well, but the approach needs much more work or has
to be replaced all together. This is mostly to save the work and myself or
someone else can revisit it.

tests/untestable/gdb/gdb_pretty_printer_test.py

@@ -25,6 +25,7 @@ outputs = [
   'seq(3, 3) = {"one", "two", "three"}',
   'Table(3, 64) = {[4] = "four", [5] = "five", [6] = "six"}',
   'Table(3, 8) = {["two"] = 2, ["three"] = 3, ["one"] = 1}',
+  '{a = 1, b = "some string"}'
 ]
 
 for i, expected in enumerate(outputs):
@@ -32,7 +33,7 @@ for i, expected in enumerate(outputs):
   gdb.flush()
 
   functionSymbol = gdb.selected_frame().block().function
-  assert functionSymbol.line == 21
+  assert functionSymbol.line == 41, str(functionSymbol.line)
 
   if i == 6:
     # myArray is passed as pointer to int to myDebug. I look up myArray up in the stack
@@ -47,6 +48,6 @@ for i, expected in enumerate(outputs):
 
   output = str(raw)
 
-  assert output == expected, output + " != " + expected
+  assert output == expected, "{0} : output: ({1}) != expected: ({2})".format(i, output, expected)
   gdb.write(f"passed\n", gdb.STDLOG)
   gdb.execute("continue")