[openjdk] : jvm_compiler and hotspot_compiler are duplicate testcasename

[openjdk] : jvm_compiler and hotspot_compiler are duplicate testcasename. Currently jvm_compiler is limited to jdk11+ and hotspot_compiler is limited to jdk8 and jdk9. So tests will not run twice, however it should be combined to one testcase to reduce confusions.

Search the test definitions and references for jvm_compiler and hotspot_compiler, then compare their JDK version restrictions. Consolidate the duplicate testcase naming while preserving the existing JDK 8, JDK 9, and JDK 11+ coverage. Done means one testcase name remains and the relevant tests still run for their intended versions.

Written by the indexing model from the issue text.