gcc: Don't use attrByPath
Get rid of tabs
Remove gcc 4.7

There is really no reason to keep it around, given that it was never
the default in Nixpkgs.
Drop pointless gcc_real variables
Drop a bunch of old unused gcc cross/debug variants
Fix indentation
Merge deterministicStdenv into the default stdenv

This means that (on Linux) strip uses
"--enable-deterministic-archives" and ld uses the
BFD_DETERMINISTIC_OUTPUT flag.
gzip: Don't depend on less

No need to make stdenv bootstrap more bloated than necessary.
flex: Clean up expression
bison: Don't run the tests

All this accomplishes is to make bison depend on flex, which in turn
depends on bison.  (So as a result, during the stdenv bootstrap, bison
gets built 6 (!) times.)
binutils: Get rid of a redundant copy of gold
binutils: Use dynamic instead of shared libraries

This reduces the size of binutils from 29 to 17 MiB.
patchelf: Update to 0.7
stdenv: Prepend SHELL=... to makeFlags

If it's appended, the user cannot override SHELL.
stdenv-linux: Prevent dependency on bootstrap-tools in the final binutils

Binutils nowadays contains ld.gold, which depends on libstdc++.  So it
needs to be built with the new GCC rather than the one from
bootstrap-tools.

Issue #1469.
gzip: Don't depend on stdenv-linux.

Issue #1469.