RFR: 8273965: some testlibrary_tests/ir_framework tests fail when c1 disabled

[Ao Qi]

These tests failed with c2-only build:

test/hotspot/jtreg/testlibrary_tests/ir_framework/tests/TestCompLevels.java
test/hotspot/jtreg/testlibrary_tests/ir_framework/tests/TestControls.java
test/hotspot/jtreg/testlibrary_tests/ir_framework/tests/TestRunTests.java

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Commit messages:
 - 8273965: some testlibrary_tests/ir_framework tests fail when c1 disabled

Changes: https://git.openjdk.java.net/jdk/pull/5576/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5576&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273965
  Stats: 3 lines in 3 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5576.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5576/head:pull/5576

PR: https://git.openjdk.java.net/jdk/pull/5576