AIX/gcc fixes.

        - Use native AIX linker
        - Search both for .a and .so libraries
        - Include only solib basename to refer to them, to workaround for lack
        for -soname option.

Patches from Andrew Miller and Andrej van der Zee.


[SVN r47293]

tools/build

@@ -1 +1 @@
-Subproject commit d065bf4c46c4ce2b4370ffc8f191c140874e0987
+Subproject commit 3e2ec364cd611ac032b65a38f145453ed35e26c0