yasm: build fixes; rebuild for cygwin

yasm/001-debian-autoconf.patch

@@ -0,0 +1,29 @@
+From ee3bc62f621e2812824b86f3efdb05f4ead134ab Mon Sep 17 00:00:00 2001
+From: Peter Johnson <johnson.peter@gmail.com>
+Date: Fri, 9 Jul 2021 13:55:15 -0700
+Subject: [PATCH] Do not use AC_HEADER_STDC
+
+This fixes compatibility with autotools 2.70+
+---
+ configure.ac | 6 ------
+ 1 file changed, 6 deletions(-)
+
+diff --git a/configure.ac b/configure.ac
+index 01b61097f..2823ecd7d 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -101,14 +101,8 @@ AM_WITH_DMALLOC
+ #
+ # Checks for header files.
+ #
+-AC_HEADER_STDC
+ AC_CHECK_HEADERS([strings.h libgen.h unistd.h direct.h sys/stat.h])
+ 
+-# REQUIRE standard C headers
+-if test "$ac_cv_header_stdc" != yes; then
+-	AC_MSG_ERROR([Standard (ANSI/ISO C89) header files are required.])
+-fi
+-
+ #
+ # Checks for typedefs, structures, and compiler characteristics.
+ #