RFR: 8305321: Remove unused exports in java.desktop [v2]

[Daniel Jeliński]

> Please review this patch that removes a number of unused exports from java.desktop native libraries.
> 
> In most cases I removed JNIEXPORT from methods and variables that are only used within a single shared library. Other than that:
> - removed `getSunFontIDs` that was reportedly used by rasterizer; as far as I could tell, rasterizer project is dead now, but if that's incorrect I can restore that export.
> - removed `colorValueID` in X11Color; that field was not used.
> - removed `J2dTraceInit` from header file. That method is only used internally by `J2dTraceImpl`.
> 
> The methods `Transform_GetInfo` and `Transform_transform` are declared in GraphicsPrimitiveMgr, but are only used in TransformHelper. Let me know if I should move them to where they are used.
> 
> The method `img_makePalette`, currently located in `share/native/libawt/awt/image/cvutils/img_colors.c`, is only used by `unix/native/common/awt/X11Color.c`; it could be moved to the same directory to avoid exporting the method from libawt. The files `img_colors.[ch]` do not have any references to other files in `cvutils`.
> 
> Manually verified that the exports are no longer present after these changes. Tier1-3 and client libs tests still pass.

Daniel Jeliński has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Merge remote-tracking branch 'origin' into desktop-exports
 - Make J2dTraceInit static
 - Remove unnecessary exports

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13261/files
  - new: https://git.openjdk.org/jdk/pull/13261/files/5f255b6d..02b46a5c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13261&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13261&range=00-01

  Stats: 337960 lines in 3525 files changed: 280898 ins; 34663 del; 22399 mod
  Patch: https://git.openjdk.org/jdk/pull/13261.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13261/head:pull/13261

PR: https://git.openjdk.org/jdk/pull/13261