RFR: 8214976: Warn about uses of functions replaced for portability [v4]

[Harold Seigel]

> Please review this new attempt to resolve JDK-8214976.  This fix adds Pragmas to generate compilation errors, when using gcc, if calling a native system function instead of the os:: version of the function.  The fix includes changes to calls in non-shared code because it is cleaner than adding PRAGMAs and, for some cases, the os:: version of a function has added value, such as asserts and RESTARTABLE.  This fix slightly changes the signature of os::abort() so it wouldn't conflict with native abort() functions.  Changes to Windows code is left for a future RFE.
> 
> This fix was tested with Mach5 tiers 1-2 on Linux, Mac OS, and Windows, Mach5 tiers 3-5 on Linux x64, and Mach5 builds of Zero, PPC, and s390.
> 
> Thanks, Harold

Harold Seigel has updated the pull request incrementally with one additional commit since the last revision:

  Use new ALLOW_CALL call macro

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7248/files
  - new: https://git.openjdk.java.net/jdk/pull/7248/files/dd1820eb..abb2b0ac

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7248&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7248&range=02-03

  Stats: 91 lines in 6 files changed: 14 ins; 48 del; 29 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7248.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7248/head:pull/7248

PR: https://git.openjdk.java.net/jdk/pull/7248