RFR: 8337563: NMT: rename MEMFLAGS to MemFlag [v2]

[Gerard Ziemski]

> Please review this cleanup, where we rename `MEMFLAGS` to `MemType`.
> 
> `MEMFLAGS` implies that we can use more than one at the same time, but those are exclusive values, so `MemType` is much more suitable name.
> 
> There is a bunch of other related cleanup that we can do, but I will leave for follow up issues such as [NMT: rename NMTUtil::flag to NMTUtil::type](https://bugs.openjdk.org/browse/JDK-8337836)

Gerard Ziemski has updated the pull request incrementally with 308 additional commits since the last revision:

 - undo MEMFLAGS to MemType
 - 8339233: Test javax/swing/JButton/SwingButtonResizeTestWithOpenGL.java#id failed: Button renderings are different after window resize
   
   Reviewed-by: honkar
 - 8338924: C1: assert(0 <= i && i < _len) failed: illegal index 5 for length 5
   
   Co-authored-by: Dean Long <dlong at openjdk.org>
   Reviewed-by: kvn, thartmann
 - 8339492: StackMapDecoder::writeFrames makes lots of allocations
   
   Reviewed-by: liach, redestad, jwaters, asotona
 - 8332901: Select{Current,New}ItemTest.java for Choice don't open popup on macOS
   
   Move SelectCurrentItemTest.java to java/awt/Choice/SelectItem/.
   Move SelectNewItemTest.java to java/awt/Choice/SelectItem/.
   Use latches to control test flow instead of delays.
   Encapsulate the common logic in SelectCurrentItemTest.
   Provide overridable checkXXX() methods to modify conditions.
   Provide an overridable method which defines where to click
   in the choice popup to select an item.
   
   Reviewed-by: honkar, prr, dnguyen
 - 8339148: Make os::Linux::active_processor_count() public
   
   Reviewed-by: dholmes, jwaters
 - 8339112: Move JVM Klass flags out of AccessFlags
   
   Reviewed-by: matsaave, cjplummer, dlong, thartmann, yzheng
 - 8336860: x86: Change integer src operand for CMoveL of 0 and 1 to long
   
   Reviewed-by: epeter, chagedorn, shade, qamai, jbhateja
 - 8325679: Optimize ArrayList subList sort
   
   Reviewed-by: liach
 - 8339131: Remove rarely-used accessor methods from Opcode
   
   Reviewed-by: asotona
 - ... and 298 more: https://git.openjdk.org/jdk/compare/9665d7f7...6d6d70e9

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20497/files
  - new: https://git.openjdk.org/jdk/pull/20497/files/9665d7f7..6d6d70e9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20497&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20497&range=00-01

  Stats: 40412 lines in 1372 files changed: 23818 ins; 9766 del; 6828 mod
  Patch: https://git.openjdk.org/jdk/pull/20497.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20497/head:pull/20497

PR: https://git.openjdk.org/jdk/pull/20497