RFR: JDK-8284178: os::commit_memory() should assert the given range [v2]

[Thomas Stuefe]

> Trivial fix to assert that ranges given to os::commit/uncommit/release_memory are not empty.
> 
> I recently hunted an error where the memory reservation failed, was not handled, and the null pointer was accidentally passed to os::commit_memory(). The resulting `mmap()` failed and this looked like a commit error, when it really was a reservation error. An assert would have saved me time.

Thomas Stuefe has updated the pull request incrementally with one additional commit since the last revision:

  Alexey-feedback

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8075/files
  - new: https://git.openjdk.java.net/jdk/pull/8075/files/f0701935..ff580166

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8075&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8075&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8075.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8075/head:pull/8075

PR: https://git.openjdk.java.net/jdk/pull/8075