bug 20366 -- do more inlining in ConsensusCore build -- gives a ~35% speedup in mutation testing

[git-p4: depot-paths = "//depot/software/common/ConsensusCore/": change = 119075]
Remove -Bsymbolic-functions flag

Unnecessary, if I am correct, and isn't supported in some older
versions of the GNU linker (CentOS...)

[Tracking bug 21562]

[git-p4: depot-paths = "//depot/software/common/ConsensusCore/": change = 119147]