dumper: avoid linker problem when libbfd depends on libsframe

A recent binutils version introduced `libsframe` and made it a
dependency of `libbfd`. This caused a linker problem in the MSYS2
project, and once Cygwin upgrades to that binutils version it would
cause the same problems there.

Let's preemptively detect the presence of `libsframe` and if detected,
link to it in addition to `libbfd`.

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

winsup/configure.ac

@@ -129,6 +129,11 @@ AC_CHECK_LIB([sframe], [sframe_decode], [BFD_LIBS="${BFD_LIBS} -lsframe"])
 AC_CHECK_LIB([zstd], [ZSTD_isError], [BFD_LIBS="${BFD_LIBS} -lzstd"])
 AC_SUBST([BFD_LIBS])
 
+AC_CHECK_LIB([sframe], [sframe_decode],
+	     AC_MSG_NOTICE([Detected libsframe; Assuming that libbfd depends on it]), [true])
+
+AM_CONDITIONAL(HAVE_LIBSFRAME, [test "x$ac_cv_lib_sframe_sframe_decode" = "xyes"])
+
 AC_CONFIG_FILES([
     Makefile
     cygwin/Makefile

winsup/utils/Makefile.am

@@ -88,6 +88,10 @@ profiler_CXXFLAGS = -I$(srcdir) -idirafter ${top_srcdir}/cygwin/local_includes -
 profiler_LDADD = $(LDADD) -lntdll
 cygps_LDADD = $(LDADD) -lpsapi -lntdll
 
+if HAVE_LIBSFRAME
+dumper_LDADD += -lsframe
+endif
+
 if CROSS_BOOTSTRAP
 SUBDIRS = mingw
 endif