RFR: 8315954: getArgumentValues002.java fails on Graal [v2]

[Doug Simon]

> This PR adds `HotSpotResolvedJavaMethod.getOopMapAt` to get the oop map for a method at a given BCI. This is required to do correct clearing of oops at OSR entry points.
> 
> As part of this addition, I needed to be able to detect requests for oop maps at invalid BCIs. For this, I added `InterpreterOopMap::has_valid_mask()`. When an oop map computation is requested for an invalid BCI, this method returns false.

Doug Simon has updated the pull request incrementally with three additional commits since the last revision:

 - generalized getLiveObjectLocalsAt to getOopMapAt
 - need to zero oop_map_buf
 - simplified getLiveObjectLocalsAt and moved it from ResolvedJavaMethod to HotSpotResolvedJavaMethod

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15705/files
  - new: https://git.openjdk.org/jdk/pull/15705/files/23b94e35..c6c6c0d8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15705&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15705&range=00-01

  Stats: 251 lines in 8 files changed: 65 ins; 120 del; 66 mod
  Patch: https://git.openjdk.org/jdk/pull/15705.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15705/head:pull/15705

PR: https://git.openjdk.org/jdk/pull/15705