RFR: 8317795: Add an ImmutableBitSetPredicate variant for bitsets <= 128 elements

[Claes Redestad]

Alternative to #16082

Name                             (unchanged) Cnt  Base   Error   Test   Error  Unit  Change
URLEncodeDecode.testEncodeLatin1           0  15 2,066 ± 0,104  1,899 ± 0,007 ms/op   1,09x (p = 0,000*)
URLEncodeDecode.testEncodeLatin1          75  15 0,934 ± 0,017  0,811 ± 0,014 ms/op   1,15x (p = 0,000*)
URLEncodeDecode.testEncodeLatin1         100  15 0,433 ± 0,060  0,389 ± 0,007 ms/op   1,11x (p = 0,008*)
  * = significant
  ```

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

Commit messages:
 - Fix and extend ImmutableBitSet test
 - Don't throw IOOBE on negative bitIndexes
 - Handle empty sets
 - Make SmallImmutableBitSetPredicate a record
 - Remove obsolete comment
 - Restore bitIndex < 0 handling
 - Add an ImmutableBitSetPredicate variant for bitsets <= 128 elements

Changes: https://git.openjdk.org/jdk/pull/16094/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16094&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8317795
  Stats: 70 lines in 2 files changed: 49 ins; 9 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/16094.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16094/head:pull/16094

PR: https://git.openjdk.org/jdk/pull/16094