RFR: 8309671: Avoid using jvmci.Compiler property to determine if Graal is enabled

[Yudi Zheng]

HeapMonitor checks if System.getProperty("jvmci.Compiler") is graal and will not enforce checking line number derived from uncommon trap debug info. However, Graal does not set this property explicitly.

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

Commit messages:
 - Avoid using jvmci.Compiler property to determine if Graal is enabled.

Changes: https://git.openjdk.org/jdk/pull/14381/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14381&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8309671
  Stats: 3 lines in 2 files changed: 0 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/14381.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14381/head:pull/14381

PR: https://git.openjdk.org/jdk/pull/14381