RFR: 8258925: configure script failed on WSL [v2]

[Yasumasa Suenaga]

> I ran configure script on WSL 1, but it failed as below:
> 
> $ bash configure --enable-debug --with-boot-jdk=/mnt/d/Java/jdk-15.0.1
> 
>     :
> 
> configure: Found potential Boot JDK using configure arguments
> configure: The command for java_to_test, which resolves as "/mnt/d/Java/jdk-15.0.1/bin/java", can not be found.
> configure: error: Cannot locate /mnt/d/Java/jdk-15.0.1/bin/java
> configure exiting with result code 1
> 
> `fixpath.sh` attempts to run `$PATHTOOL` with `.exe` if it fails with original path, but `.exe` would not be added even if `$path.exe` exists.

Yasumasa Suenaga 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:

 - Save original path
 - Merge remote-tracking branch 'upstream/master' into JDK-8258925
 - 8258925: configure script failed on WSL

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1889/files
  - new: https://git.openjdk.java.net/jdk/pull/1889/files/284b3a2a..286a1f64

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1889&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1889&range=00-01

  Stats: 19697 lines in 830 files changed: 3395 ins; 7379 del; 8923 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1889.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1889/head:pull/1889

PR: https://git.openjdk.java.net/jdk/pull/1889