Expose full command-lines to other Win32 processes by default

In the Cygwin project, it was decided that the command-line of Cygwin
processes, as shown in the output of `wmic process list`, would suffer
from being truncated to 32k (and is transmitted to the child process via
a different mechanism, anyway), and therefore only the absolute path of
the executable is shown by default.

Users who would like to see the full command-line (even if it is
truncated) are expected to set `CYGWIN=wincmdln` (or, in MSYS2's case,
`MSYS=wincmdln`).

Seeing as MSYS2 tries to integrate much better with the surrounding
Win32 ecosystem than Cygwin, it makes sense to turn this on by default.

Users who wish to suppress it can still set `MSYS=nowincmdln`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

winsup/cygwin/globals.cc

@@ -70,7 +70,7 @@ bool allow_glob = true;
 bool ignore_case_with_glob;
 bool pipe_byte = true; /* Default to byte mode so that C# programs work. */
 bool reset_com;
-bool wincmdln;
+bool wincmdln = true;
 winsym_t allow_winsymlinks = WSYM_deepcopy;
 bool disable_pcon;
 bool winjitdebug = false;

winsup/doc/cygwinenv.xml

@@ -90,7 +90,7 @@ time and when handles are inherited.  Defaults to set.</para>
 <listitem>
 <para><envar>(no)wincmdln</envar> - if set, the windows complete command
 line (truncated to ~32K) will be passed on any processes that it creates
-in addition to the normal UNIX argv list.  Defaults to not set.</para>
+in addition to the normal UNIX argv list.  Defaults to set.</para>
 </listitem>
 
 <listitem>