gitignore some build products

cae357e7 · Travis Cross · 5e3c5db7 · cae357e7
--- a/libs/.gitignore
+++ b/libs/.gitignore
@@ -523,6 +523,11 @@ missing
 /spandsp/doc/Makefile.in
 /spandsp/Makefile
 /spandsp/Makefile.in
+/spandsp/m4/libtool.m4
+/spandsp/m4/ltoptions.m4
+/spandsp/m4/ltsugar.m4
+/spandsp/m4/ltversion.m4
+/spandsp/m4/lt~obsolete.m4
 /spandsp/spandsp-sim/Makefile
 /spandsp/spandsp-sim/Makefile.in
 /spandsp/src/at_interpreter_dictionary.h