RFR: 8231471: Obsolete -XX:CompilationPolicyChoice

[Claes Redestad]

Hi,

CompilationPolicyChoice was deprecated in 13 with the goal of obsoleting
it in 14.

Webrev: http://cr.openjdk.java.net/~redestad/8231471/webrev.00/
Bug:    https://bugs.openjdk.java.net/browse/JDK-8231471

Since removing CompilationPolicyChoice makes it impossible to select and
run the StackWalkCompPolicy I've removed that code, along with 2 develop
flags only used by it.

StackWalkCompPolicy was the C2 default before 6, but abandoned in favor
of the simpler C1 policy since it resulted in better startup and similar
or better performance[1]. The choice to go back has remained as an
undocumented options, and we've seen no reports of it being used.

Testing: tier1-3

Thanks!

/Claes