Provide <triplet>-<tool> wrappers and links to many llvm tools

Provide wrappers named <triplet>-gcc and <triplet>-g++ as well,
to ease cross compilation with e.g. autotools, to allow just
specifying --host=<triplet>.

Provide wrappers for objdump and ld that provide specific output
that autotools look for.

Provide <triplet>-strip as a symlink to /bin/true, since there is
no strip tool available yet (and llvm-objcopy doesn't support
COFF yet).

README.md

@@ -36,15 +36,10 @@ To build the toolchain in Docker, run:
 In addition to building the toolchain itself (just like `build-all.sh` does),
 this also builds a few demo apps to show and verify that the toolchain works.
 
-Other branches in this repo contain patches that might not have been
+Other branches in this repo might contain patches that might not have been
 merged upstream yet, and tests of building third party projects using
 the toolchain (in the branch `demoapps`).
 
-For building projects that need more than just specifying
-`CC=<triplet>-clang`, there is more (more or less hacky and in-progress)
-setup for providing a larger selection of the tools that GNU binutils
-normally provides, in the branch `tools`.
-
 Individual components of the toolchain can be (re)built by running
 the standalone shellscripts listed within `build-all.sh`. However, if
 the source already is checked out, no effort is made to check out a