RFR: 8300113: C2: Single-bit fields with signed type in TypePtr after JDK-8297933

[Aleksey Shipilev]

See the description in the bug. Attention @rwestrel.
The solution is to use `uint` like the rest of C2 and other `:1` fields there.

Additional testing:
 - [x] Linux x86_64 fastdebug hotspot:tier1

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Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/11989/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11989&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8300113
  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/11989.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11989/head:pull/11989

PR: https://git.openjdk.org/jdk/pull/11989