Update to 7.12.1
Updating gdb to the last stable version and cleaning it up.

PR: 217090
Submitted by: luca.pizzamiglio@gmail.com (maintainer)

PR: 216027

• Recognizing the compiler to adopt options properly Reported by: julian@FreeBSD.org

PR: 216132

• Fixing the segmentation fault, but arm core dump not yet usable Reported by: Mark Millard