[Bug middle-end/114540] Use of atoi in varasm.cc (decode_reg_name_and_count) allows invalid registers

[heiko at hexco dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114540

--- Comment #4 from Heiko Eißfeldt <heiko at hexco dot de> ---
After realizing my error in the previous patch (relying on an ERANGE check for
the wanted integer type instead of a check of long type range) I manually
tested my corrected patch. Corner cases behave like other invalid values and
give the same error message consistenly now.

Still working on a DG test case...
Is there any 'hello world' DG example?

Thanks!