Change to recommanded m4/-style small files

m4/ccalias.m4

@@ -0,0 +1,16 @@
+dnl Check whether the target supports symbol aliases.
+dnl This is a mdbtools specific version
+dnl TODO: Check if gnulib version works, and add serial
+
+dnl Code copied from libgomp
+AC_DEFUN([AM_GCC_ATTRIBUTE_ALIAS], [
+  AC_CACHE_CHECK([whether the target supports symbol aliases],
+		 am_cv_gcc_have_attribute_alias, [
+  AC_LINK_IFELSE([AC_LANG_PROGRAM([
+void foo(void) { }
+extern void bar(void) __attribute__((alias("foo")));],
+    [bar();])], am_cv_gcc_have_attribute_alias=yes, am_cv_gcc_have_attribute_alias=no)])
+  if test $am_cv_gcc_have_attribute_alias = yes; then
+    AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
+      [Define to 1 if the target supports __attribute__((alias(...))).])
+  fi])