The .config and config.log are attached. (In .config, I use 4.6.2 for
gcc trunk as workaround).

In config.log, the final error is
  error: Link tests are not allowed after GCC_NO_EXECUTABLES

In config.log, you can find lots of error:
  xgcc: error: unrecognized command line option '-EL'

I compare gcc-4.6 and trunk configure. Seam gcc-4.6 has bugs.
LDFLAGS_FOR_TARGET is always empty. gcc-4.6 can build. And from
trunk's ChangeLog, you can find

2011-05-08  Doug Kwan  <dougkwan@google.com>

        * configure.ac: Propagate LDFLAGS_FOR_TARGET.

I am not sure option '-EL' is the root cause. But without it, the
trunk can build.

Thanks!
-Zhenqiang