RFR: 8256675: Zero: purge biased locking support [v2]

[Aleksey Shipilev]

> Biased locking support was always disabled for C++ interpreter. Zero seems to have inherited that, see block in `arguments.cpp`:
> 
> #ifdef ZERO
>   // Clear flags not supported on zero.
>   FLAG_SET_DEFAULT(ProfileInterpreter, false);
>   FLAG_SET_DEFAULT(UseBiasedLocking, false);
>   LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedOops, false));
>   LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedClassPointers, false));
> #endif // ZERO
> 
> But `zero/bytecodeInterpreter.cpp` still has paths that imply biased locking support. Seeing that biased locking can go away, and the cost/benefit balance of supporting it in Zero, it makes more sense to purge the long-time-disabled biased locking support from Zero.
> 
> Additional testing:
>  - [x] Ad-hoc benchmark runs with `-XX:(-|+)UseBiasedLocking` (Zero is so slow that BL does not matter)

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Remove more has_bias_pattern checks

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1322/files
  - new: https://git.openjdk.java.net/jdk/pull/1322/files/0a2c8487..f7fa09fa

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1322&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1322&range=00-01

  Stats: 34 lines in 1 file changed: 2 ins; 1 del; 31 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1322.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1322/head:pull/1322

PR: https://git.openjdk.java.net/jdk/pull/1322