[9] RFR(M): 7194669: CodeCache::mark_for_deoptimization should avoid verifying dependencies multiple times

[Roland Westrelin]

Hi Albert,

> Problem:
> The dependency verification code in CodeCache::mark_for_deoptimization walks over all live nmethods in the code cache and checks all dependencies for each nmethod. This leads to checking the same dependency multiple times which can take a huge amount of time.

Isn’t it only when VerifyDependencies is true on non product build? Why does it matter?

Roland.