Inhibit mingw CRT's auto-globbing of command line arguments

For some reason by default the mingw C Runtime takes it upon itself to
expand program arguments that look like shell globbing characters. That
has caused much scratching of heads and mis-attribution of the causes of
some TAP test failures, so stop doing that.

This removes an inconsistency with Windows binaries built with MSVC,
which have no such behaviour.

Per suggestion from Noah Misch.

Backpatch to all live branches.

Discussion: https://postgr.es/m/20220423025927.GA1274057@rfd.leadboat.com

src/common/exec.c

@@ -25,6 +25,11 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+/* Inhibit mingw CRT's auto-globbing of command line arguments */
+#if defined(WIN32) && !defined(_MSC_VER)
+extern int _CRT_glob = 0; /* 0 turns off globbing; 1 turns it on */
+#endif
+
 #ifndef FRONTEND
 /* We use only 3- and 4-parameter elog calls in this file, for simplicity */
 /* NOTE: caller must provide gettext call around str! */