[jdk11u-dev] RFR: 8283451: C2: assert(_base == Long) failed: Not a Long

[Goetz Lindenmaier]

I backport this for parity with 11.0.16-oracle. 

The change applies clean. But the test uses flags StressCCP StressIGVN StressSeed not known in 11.
I removed these flags. This makes the second @run command pointless, removed too.

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Commit messages:
 - Backport fabde3b7b8ed5e576febe8138c14696ccdf636d5

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/1013/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=1013&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283451
  Stats: 78 lines in 2 files changed: 76 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/1013.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/1013/head:pull/1013

PR: https://git.openjdk.java.net/jdk11u-dev/pull/1013