RFR: 8301994: Remove unused code from awt_List.cpp [v2]

[Rajat Mahajan]

> Remove commented out/ unused code from awt_List.cpp, which has been commented out since 2007, when the code was moved to Mercurial.
> The test ScrollPaneLimitation.java has been opened under [JDK-8306137](https://bugs.openjdk.org/browse/JDK-8306137), and it should be safe to remove this code now.

Rajat Mahajan has updated the pull request incrementally with one additional commit since the last revision:

  Update awt_List.cpp
  
  removed extra blank line at the end of the function.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17378/files
  - new: https://git.openjdk.org/jdk/pull/17378/files/6d1045d0..fe1ec21c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17378&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17378&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/17378.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17378/head:pull/17378

PR: https://git.openjdk.org/jdk/pull/17378