Fix android-specific build (use of unassigned variable).
[corlib] Replace manual array resize with Resize call
[mcs] Report all failure errors in lambda conversions. Fixes #16513
[mcs] Report nice error instead of crash for cyclic type forwarders. Fixes #16385
[sgen] Never invoke libc’s memmove() or bzero().

Those two functions are not guaranteed to do word-atomic copying or
zeroing under any circumstances.  memmove() on OSX, for instance,
has an SSE optimized variant that, if source and destination are 8-byte,
but not 16-byte aligned, will copy the first 8 bytes byte-wise, which can
crash SGen.

Fixes https://bugzilla.xamarin.com/show_bug.cgi?id=16449.
[sdb] Support a setpgid=y/n option to --debugger-agent.