RFR: 8256862: Several java/foreign tests fail on x86_32 platforms [v2]

[Jorn Vernee]

> This patch fixes several failures on x86_32 of java/foreign tests.
> 
> This is mostly done by disabling the failing tests, but the impl of CLinker is also adjusted ton properly detect 32 bit platforms as unsupported.
> 
> CLinker is specified to fail in the initializer on unsupported platforms, and a test is added to verify this as well.
> 
> Note that this adds requires clauses to the failing tests that explicitly enumerate all available platforms, so this should fix the test failures on other platforms as well.
> 
> https://bugs.openjdk.java.net/browse/JDK-8256757 is filed for the remaining failure in TestStringLatin1IndexOfChar.
> 
> CSR link: https://bugs.openjdk.java.net/browse/JDK-8256863

Jorn Vernee has updated the pull request incrementally with one additional commit since the last revision:

  Exclude TestNulls as well

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1386/files
  - new: https://git.openjdk.java.net/jdk/pull/1386/files/bb3f4497..0ea11786

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1386&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1386&range=00-01

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1386.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1386/head:pull/1386

PR: https://git.openjdk.java.net/jdk/pull/1386