RFR: 8302147: Speed up compiler/jvmci/compilerToVM/IterateFramesNative.java

[Emanuel Peter]

This test took about `18 sec`, with this fix it should take about `3 sec`, so a `6x` speedup.

I discussed it with @woess the original author of the test. He suggested this fix.
The first run statement still works as before, the second one, which sets `-Dcompiler.jvmci.compilerToVM.IterateFramesNative.checkCompiled=true` and has `CHECK_COMPILED == true` now only runs one iteration. This should be sufficient, we see that the whitebox checks successfully that the methods were compiled.

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Commit messages:
 - different fix
 - 8302147: Speed up compiler/jvmci/compilerToVM/IterateFramesNative.java

Changes: https://git.openjdk.org/jdk/pull/12496/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12496&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8302147
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/12496.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12496/head:pull/12496

PR: https://git.openjdk.org/jdk/pull/12496