RFR: 8311043: Remove trailing blank lines in source files

[Leo Korinth]

Remove trailing "blank" lines in source files.

I like to use global-whitespace-cleanup-mode, but I can not use it if the files are "dirty" to begin with. This fix will make more files "clean". I also considered adding a check for this in jcheck for Skara, however it seems jcheck code handling hunks does not track end-of-files. Thus I will only clean the files.

The fix removes trailing lines matching ^[[:space:]]*$ in

- *.java
- *.cpp
- *.hpp
- *.c
- *.h 

I have applied the following bash script to each file:

    file="$1"
    
    while [[ $(tail -n 1 "$file") =~ ^[[:space:]]*$ ]]; do
        truncate -s -1 "$file"
    done

`git diff --ignore-space-change --ignore-blank-lines  master` displays no changes
`git diff --ignore-blank-lines  master` displays one change

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

Commit messages:
 - h
 - c
 - hpp
 - cpp
 - 8311043: Remove trailing blank lines in source files

Changes: https://git.openjdk.org/jdk/pull/14698/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14698&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8311043
  Stats: 4529 lines in 4382 files changed: 0 ins; 4529 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/14698.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14698/head:pull/14698

PR: https://git.openjdk.org/jdk/pull/14698