[newlib-cygwin] Cygwin: do not build MinGW testsuite/cygrun --with-cross-bootstrap

[Yaakov Selkowitz]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=cf8aa432844d912d0a0d2d6bebe2c3de22be0914

commit cf8aa432844d912d0a0d2d6bebe2c3de22be0914
Author: Yaakov Selkowitz <yselkowi@redhat.com>
Date:   Sun Jan 9 22:32:56 2022 -0500

    Cygwin: do not build MinGW testsuite/cygrun --with-cross-bootstrap

Diff:
---
 winsup/testsuite/Makefile.am | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/winsup/testsuite/Makefile.am b/winsup/testsuite/Makefile.am
index 4b8c7dbb7..ac68934d0 100644
--- a/winsup/testsuite/Makefile.am
+++ b/winsup/testsuite/Makefile.am
@@ -61,4 +61,6 @@ EXTRA_DEJAGNU_SITE_CONFIG = site-extra.exp
 clean-local:
 	rm -f *.log *.exe *.exp *.bak *.stackdump winsup.sum
 
+if CROSS_BOOTSTRAP
 SUBDIRS = cygrun
+endif