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: I09b88e6b4792c99140a73a4ceb11d2896ee13562
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/.gitignore b/.gitignore
index 2d173c1..2d5cc7e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,6 +22,7 @@
 /autoscan.log
 /autoscan-*.log
 /aclocal.m4
+/aminclude_static.am
 /compile
 /config.guess
 /config.h.in