[gcc] backport of gcc patch to #gcc-7-branch

[Vineet Gupta]

Hi,

As part of porting glibc to ARC one of the pre-req is to get it to build with 
upstream toolchain components. The patch 927c0132251f ("[ARC] Configure script to 
allow non uclibc based triplets") seems to be present in gcc #master, but not in 
#gcc-7-branch. Can it be backported to gcc 7 please.

Thx,
-Vineet