[PATCH 0/2] Change Ada type names reported by Python

[Tom Tromey]

This series changes the Python code to report the "decoded" (aka
"demangled") Ada type names.  This is arguably more correct, as the
encoded names are compiler-synthesized and surprising to users; also
it is less fragile, because the type names are generally changing
anyway as we move the compiler to "minimal encodings".

This is split in 2 parts because originally the first patch came from
my psymtab scanner rewrite; however, we realized in review that that
series will actually require a second parameter to ada_decode.  At
that point, though, it was more convenient to keep the patches
separate.

Tested on x86-64 Fedora 32.

Tom