[jdk11u-dev] RFR: 8257709: C1: Double assignment in InstructionPrinter::print_stack

[Elif Aslan]

Clean backport. This double assignment causes undefined behavior.

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

Commit messages:
 - Backport 563b268c8f23a1f9f5e70065419d4e8661d1d0b4

Changes: https://git.openjdk.org/jdk11u-dev/pull/3115/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=3115&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8257709
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/3115.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/3115/head:pull/3115

PR: https://git.openjdk.org/jdk11u-dev/pull/3115