[newlib-cygwin] Cygwin: Add rule to testsuite Makefile to regenerate it when needed

[Jon TURNEY]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=7b65f83c229b6dc49b1911da9c71d718bcd8e0e3

commit 7b65f83c229b6dc49b1911da9c71d718bcd8e0e3
Author: Jon Turney <jon.turney@dronecode.org.uk>
Date:   Mon Nov 2 21:53:37 2020 +0000

    Cygwin: Add rule to testsuite Makefile to regenerate it when needed

Diff:
---
 winsup/testsuite/Makefile.in | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/winsup/testsuite/Makefile.in b/winsup/testsuite/Makefile.in
index 1b0d0de59..0e7f6ff1e 100644
--- a/winsup/testsuite/Makefile.in
+++ b/winsup/testsuite/Makefile.in
@@ -165,3 +165,6 @@ cygrun.o: cygrun.c
 
 cygrun.exe : cygrun.o
 	${MINGW_FE} $(CC) ${MINGW_LDFLAGS} -o $@ $<
+
+Makefile: Makefile.in $(srcdir)/configure config.status
+	$(SHELL) config.status