RFR: 8287517: C2: assert(vlen_in_bytes == 64) failed: 2 [v2]

[Sandhya Viswanathan]

> Fixed the assertion in load_iota_indices when the length passed is less than 4.
> Also fixed the missing break in x86.ad match_rule_supported_vector() for PopulateIndex case.

Sandhya Viswanathan has updated the pull request incrementally with one additional commit since the last revision:

  Add regression test

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8961/files
  - new: https://git.openjdk.java.net/jdk/pull/8961/files/84973dba..1939a73a

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8961&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8961&range=00-01

  Stats: 65 lines in 1 file changed: 65 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8961.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8961/head:pull/8961

PR: https://git.openjdk.java.net/jdk/pull/8961