The cctools-port linker links against libraries from clang (for LTO),
which have different SONAMEs depending on the clang version. Which means
the linker needs to be used along the same version of clang it was built
against. Thus we also make it depend on linux64-clang-7.
But changing the dependency is not enough, cf. bug 1471905, so also
touch its build script, which it turns out, we need to do anyways
because llvm-dsymutil was renamed to dsymutil.
Relatedly, all toolchains that are built using cctools-port need to use
linux64-clang-7 too.
Building compiler-rt 7 with the OSX 10.11 SDK fails because of some
newer APIs being used in compiler-rt for xray, but this is not a feature
we use, so disable that.
Differential Revision: https://phabricator.services.mozilla.com/D6766
The toolchain build scripts are currently defining the tooltool
manifest they use on their own. We move the definitions to the
taskcluster job definitions to normalize on everything using that.
Also use the same cctools as cross-mac builds of Firefox.
Do dummy changes to the corresponding build scripts so that the builds
are force triggered (toolchain builds are not triggered automatically
when the tooltool manifest they use changes yet).
