RFR(XS): 8245126 Kitchensink fails with: assert(!method->is_old()) failed: Should not be installing old methods

[serguei.spit...@oracle.com]

Please, review a fix for:
  https://bugs.openjdk.java.net/browse/JDK-8245126

Webrev:
  http://cr.openjdk.java.net/~sspitsyn/webrevs/2020/kitchensink-comp.1/


Summary:
  The Kitchensink stress test with the Instrumentation module enabled does
  a lot of class retransformations in parallel with all other stressing.
  It provokes the assert at the compiled code installation time:
    assert(!method->is_old()) failed: Should not be installing old methods

  The problem is that the CompileBroker::invoke_compiler_on_method in C2 version
  (non-JVMCI tiered compilation) is missing the check that exists in the JVMCI
  part of implementation:

2148     // Skip redefined methods
2149     if (target_handle->is_old()) {
2150       failure_reason = "redefined method";
2151       retry_message = "not retryable";
2152       compilable = ciEnv::MethodCompilable_never;
2153     } else {
. . .
2168     }

  The fix is to add this check.

Testing:
  Ran Kitchensink test with the Instrumentation module enabled in mach5
  multiple times for 100 times. Without the fix the test normally fails
  a couple of times in 200 runs. It does not fail with the fix anymore.
  Will also submit hs tiers1-5.

Thanks,
Serguei