RFR: 8331603: Cleanup native AbstractSurface methods getRGBImpl, setRGBImpl [v2]

[Ambarish Rapte]

> The parameter "offset" is not validated in the 2 native methods getRGBImpl() and setRGBImpl() of com.sun.pisces.AbstractSurface (in JAbstractSurface.c).
> The PR adds the "offset < 0" check to both the methods.

Ambarish Rapte has updated the pull request incrementally with one additional commit since the last revision:

  const vars

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1497/files
  - new: https://git.openjdk.org/jfx/pull/1497/files/7424f752..3e4a8987

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1497&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1497&range=00-01

  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jfx/pull/1497.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1497/head:pull/1497

PR: https://git.openjdk.org/jfx/pull/1497