Sync gdb test with java-1.8.0-openjdk.
Improve architecture restrictions for the gdb test.
Replace -mstackrealign with -mincoming-stack-boundary=2 -mpreferred-stack-boundary=4 on x86_32 for stack alignment
Explicitly list JIT architectures rather than relying on those with slowdebug builds
Disable the serviceability agent on Zero architectures even when the architecture itself is supported
Add backport of JDK-8257794 to fix bogus assert on slowdebug x86-32 Zero builds
Give javadoc-zip its own Provides, next to the plain javadoc ones
Related: rhbz#2052834
Andrew Hughes