BUG #16080: pg_ctl is failed if a fake cmd.exe exist in the current directory.

The following bug has been logged on the website:

Bug reference:      16080
Logged by:          cili
Email address:      cilizili@protonmail.com
PostgreSQL version: 12.0
Operating system:   Microsoft Windows [Version 10.0.18362.418]
Description:

If a fake cmd.exe exits in the current directory, pg_ctl is failed to
start.

Instructions:
# cd %TEMP%
# "c:\Program Files\PostgreSQL\12\bin\pg_ctl.exe" initdb -D test
# copy %windir%\system32\calc.exe cmd.exe
# "c:\Program Files\PostgreSQL\12\bin\pg_ctl.exe" start -D test
waiting for server to start.... stopped waiting
pg_ctl: could not start server
Examine the log output.

Expected:
The PostgreSQL is started.

Actual:
The Windows calculator instead of PostgreSQL is started.