Force AIX xlc to fail and not generate object code if the source code has

compiled with errors. This behaviour is needed for autoconf macros which
rely on the ability to compile with or without errors, and is safer than
xlc's default of failing only upon severe errors.

configure.ac

@@ -342,6 +342,9 @@ if test "x$RECENTAIX" = "xyes"; then
          dnl the optimizer assumes that pointers can only point to
          dnl an object of the same type.
          CFLAGS="$CFLAGS -qnoansialias"
+         dnl Force AIX xlc to stop after the compilation phase, and not
+         dnl generate object code, when the source compiles with errors.
+         CFLAGS="$CFLAGS -qhalt=e"
        )
 fi