RFR: 8273373: Zero: Cannot invoke JVM in primordial threads on Zero [v3]

[Aleksey Shipilev]

> See the bug for more discussion.
> 
> Additional testing:
>  - [x] Linux Zero x86_64 passes most gtests now (there are unrelated failures)
>  - [x] Linux Zero x86_32 passes most gtests now (there are unrelated failures)

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Even more conservative patch

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5376/files
  - new: https://git.openjdk.java.net/jdk/pull/5376/files/29021f40..b8b5774c

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5376&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5376&range=01-02

  Stats: 67 lines in 1 file changed: 24 ins; 16 del; 27 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5376.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5376/head:pull/5376

PR: https://git.openjdk.java.net/jdk/pull/5376