RFR: 8317332: Prepare security for permissive- [v2]

[Julian Waters]

> Prepares java.security.jgss for the permissive- compiler switch by
> 
> - Adding scopes so goto doesn't jump over unitialized locals in sspi.cpp
> - Adding a static modifier to a mismatched method declaration in NativeCreds.c, as the definition is static

Julian Waters has updated the pull request incrementally with one additional commit since the last revision:

  Leave out c prefix in sspi.cpp for now

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15996/files
  - new: https://git.openjdk.org/jdk/pull/15996/files/58ef97c9..f38d27a0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15996&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15996&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/15996.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15996/head:pull/15996

PR: https://git.openjdk.org/jdk/pull/15996