[jdk11u-dev] RFR: 8258703: Incorrect 512-bit vector registers restore on x86_32

[Aleksey Shipilev]

Currently, there are x86_32 failures in GHA:


compiler/runtime/Test7196199.java 
compiler/runtime/safepoints/TestRegisterRestoring.java 
compiler/vectorization/TestVectorsNotSavedAtSafepoint.java


This backport is supposed to fix at least one of them.

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Commit messages:
 - Backport 216c2ec077447718ae912831647250561a969f4e

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/214/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=214&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8258703
  Stats: 12 lines in 1 file changed: 6 ins; 5 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/214.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/214/head:pull/214

PR: https://git.openjdk.java.net/jdk11u-dev/pull/214