RFR(S): 8191818: [MVT] CTW fails with "assert(vk->is__Value()) failed: unexpected value type klass"

[Tobias Hartmann]

Hi,

please review the following patch:
https://bugs.openjdk.java.net/browse/JDK-8191818
http://cr.openjdk.java.net/~thartmann/8191818/webrev.00/

The problem is that C->env()->___Value_klass() is NULL because __Value is not loaded if !EnableMVT && !EnableValhalla.
I've already fixed this for "build-in" CTW with JDK-8183233 [1] but the problem still exists with ReplayCompiles or
compilations triggered through the WhiteBox API implementation of CTW.

I've moved the check into CompileBroker::compile_method() to catch all compilations.

Thanks,
Tobias

[1] https://bugs.openjdk.java.net/browse/JDK-8183233