RFR: 8306976: UTIL_REQUIRE_SPECIAL warning on grep

[xpbob]

hi

bash configure

There is an warning message

The following warnings were produced. Repeated here for convenience:
WARNING: Ignoring value of GREP from the environment. Use command line variables instead.

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

Commit messages:
 - 8306976: UTIL_REQUIRE_SPECIAL warning on grep

Changes: https://git.openjdk.org/jdk/pull/13685/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13685&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8306976
  Stats: 2 lines in 1 file changed: 1 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13685.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13685/head:pull/13685

PR: https://git.openjdk.org/jdk/pull/13685