Fooling around with crosstool-ng hg version, I happened to get gcc 
configure to yell at me right off. Promising.

The breakage is in build-cc-core-pass-2, saying
[ERROR]    configure: error: 
[CFG  ]    *** LIBRARY_PATH shouldn't contain the current directory when
[CFG  ]    *** building gcc. Please change the environment variable
[CFG  ]    *** and run configure again.

I figure this could bite others, and I see no good reason for LIBRARY_PATH 
to be set at this point.

The reason I had them set in the first place was due to some nvidia OpenCL 
libraries.

Patch attached to unset these two.

--
-erik	http://useofwords.blogspot.com/