how to limit autofill of executables in 'cygwin-bash' to a list of 'extensions'

[Linda Walsh]

I have a long standing problem under cygwin in that when I type
a prefix of 1 or more executables and hit the expand character (ESC),
it lists out all the DLL's in my system path.

I NEVER want to execute libraries directly.  Many or most are
not executables -- yet bash lists them.  In Windows, the
'exec' bit doesn't mean it is an executable -- it means
it is executable code that can be loaded into an executable
segment of memory.  Files that don't have that bit set get
loaded into memory (on properly configured systems) that
has a "NX:Not eXecutable" bit set, that disallows execution.

Anyway -- it's more of an OS thing than a strictly a user
thing -- and Windows uses a registry String value:
[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session 
Manager\Environment\PathExt]
(example value = ".COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC")
(
 cygwin bash on win64:
#> 
PATHEXT="$(<'/proc/registry64/HKEY_LOCAL_MACHINE/SYSTEM/ControlSet001/Control/Session 
Manager/Environment/PATHEXT')"
)

to control what files are executable. 

Not saying this is a bash bug -- as it's really more of how bash
should be configured on windows platforms (I suppose the same would
be true for any MING versions of bash as well), but how can bash
be setup to only display the executables appropriate for the 
given OS?

Thanks!
Linda