autotools: Fix for autoconf-archive 2019.01.19

The code coverage macros from the archive changed in a backward
incompatible way. This adds a workaround to autodetect either version
and do the right thing.

Change-Id: Ibb95188264f3fece4a18dbcb98f3e90f8350ff21
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/.gitignore b/.gitignore
index b6813f2..8164d51 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,6 +27,8 @@
 .dirstamp
 .libs
 /aclocal.m4
+/aminclude_static.am
+/autom4te.cache
 /build-aux
 /config.h
 /config.h.in