RFR: 8345237: 32-bit Zero builds fail with assert(has_klass_gap()) failed: precondition

[Aleksey Shipilev]

[JDK-8305895](https://bugs.openjdk.org/browse/JDK-8305895) started to wrap `oopDesc::set_klass_gap()` calls with `oopDesc::has_klass_gap()`, but missed a spot in Zero. So now 32-bit Zero builds fail like this:


=== Output from failing command(s) repeated here ===
* For target buildtools_create_symbols_javac__the.COMPILE_CREATE_SYMBOLS_batch:
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/home/shade/trunks/jdk/src/hotspot/share/oops/oop.inline.hpp:167), pid=1592865, tid=1592897
# assert(has_klass_gap()) failed: precondition


Additional testing:
 - [x] Linux x86_32 zero fastdebug build now passes

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

Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/22453/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22453&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8345237
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22453.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22453/head:pull/22453

PR: https://git.openjdk.org/jdk/pull/22453