Fix dejagnu.h linkage

probe for -fgnu89-inline and use it.
See https://gcc.gnu.org/bugzilla//show_bug.cgi?id=63613
Fixes [GH #2]

Add dejagnu to cygwin and ubuntu/travis. msys2 dejagnu is not picked up,
macos not tested on travis.

.appveyor.yml

@@ -58,8 +58,7 @@ init:
   - if "%PLATFORM%"=="x64" set P=64
   - if "%CYGWIN%"=="1" set CYG_ROOT=c:\cygwin%P%
   - if "%CYGWIN%"=="1" appveyor DownloadFile http://cygwin.com/%ISETUP%.exe -FileName %CYG_ROOT%\setup.exe
-  - if "%CYGWIN%"=="1" %CYG_ROOT%\setup.exe -qnNdO -R "%CYG_ROOT%" -s "%CYG_MIRROR%" -l "%CYG_ROOT%\var\cache\setup" -P libxml2,libxml2-devel,libiconv-devel,python2-devel,python2-libxml2,swig,help2man,libcrypt-devel
-  # skip dejagnu. fails to link
+  - if "%CYGWIN%"=="1" %CYG_ROOT%\setup.exe -qnNdO -R "%CYG_ROOT%" -s "%CYG_MIRROR%" -l "%CYG_ROOT%\var\cache\setup" -P libxml2,libxml2-devel,libiconv-devel,python2-devel,python2-libxml2,swig,help2man,libcrypt-devel,dejagnu
 
 build_script:
   - if "%CYGWIN%"=="1" set PATH=%CYG_ROOT%\bin;c:\Windows\system32;c:\Windows;c:\Windows\system32\Wbem

.travis.yml

@@ -12,6 +12,7 @@ addons:
       - python-libxml2
       - swig
       - help2man
+      - dejagnu
 matrix:
   fast_finish: true
   include:

configure.ac

@@ -154,6 +154,13 @@ then
     [Define if __attribute__((visibility("default"))) is supported.])
 fi
 
+if test x$ac_cv_header_dejagnu_h = xyes; then
+  dnl check if dejagnu needs -fgnu89-inline
+  dnl https://gcc.gnu.org/bugzilla//show_bug.cgi?id=63613
+  AX_CHECK_COMPILE_FLAG([-fgnu89-inline],[DEJAGNU_CFLAGS=-fgnu89-inline],[DEJAGNU_CFLAGS=])
+  AC_SUBST([DEJAGNU_CFLAGS])
+fi
+
 dnl until we can make a release, favor no -O2 optims.
 dnl it's fast enough and better for debugging.
 dnl if test x$ac_compiler_gnu = xyes; then

test/testcases/Makefile.am

@@ -1,7 +1,7 @@
 AUTOMAKE_OPTIONS = dejagnu
 
 WARN_CFLAGS = @WARN_CFLAGS@
-AM_CFLAGS = -I$(top_srcdir)/include -I$(top_srcdir)/src $(WARN_CFLAGS)
+AM_CFLAGS = -I$(top_srcdir)/include -I$(top_srcdir)/src $(WARN_CFLAGS) @DEJAGNU_CFLAGS@
 LDADD   = $(top_builddir)/src/libredwg.la -lm
 
 bits_test_LDADD = $(LDADD) $(top_builddir)/src/bits.lo