[s390x] Put compiler-rt in runtimes

[DavidSpickett]

Summary

This moves compiler-rt from ENABLE_PROJECTS, to ENABLE_RUNTIMES
for these bots:

• clang-s390x-linux
• clang-s390x-linux-multistage
• clang-s390x-linux-lnt

This matches the recommended way to build compiler-rt.

getClangCMakeBuildFactory's current default is enable_runtimes=None
which means the runtimes build is not used. "auto" puts anything known
to be a runtimes project into the list of runtimes instead of projects.

[uweigand]

LGTM, thanks for taking care of s390x!

[DavidSpickett]

Landed as https://github.com/llvm/llvm-zorg/commit/cf2edff0be6811e1d33aada3f17523429b1fda92

buildbot/osuosl/master/config/builders.py

# Clang builders.
     {'name' : "clang-s390x-linux",
     'tags'  : ["clang"],
     'workernames' : ["systemz-1"],
     'builddir': "clang-s390x-linux",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     jobs=4,
                     clean=False,
                     checkout_lld=False,
+                    enable_runtimes="auto",
                     useTwoStage=False,
                     stage1_config='Release',
                     extra_cmake_args=[
                         "-DLLVM_CCACHE_BUILD=ON",
                         "-DLLVM_ENABLE_ASSERTIONS=ON",
                         "-DLLVM_LIT_ARGS=-v -j4 --param run_long_tests=true"])},
 
     {'name' : "clang-s390x-linux-multistage",
     'tags'  : ["clang"],
     'workernames' : ["systemz-1"],
     'builddir': "clang-s390x-linux-multistage",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     jobs=4,
                     clean=False,
                     checkout_lld=False,
+                    enable_runtimes="auto",
                     useTwoStage=True,
                     stage1_config='Release',
                     stage2_config='Release',
                     extra_cmake_args=[
                         "-DLLVM_CCACHE_BUILD=ON",
                         "-DLLVM_ENABLE_ASSERTIONS=ON"])},
 
     {'name' : "clang-s390x-linux-lnt",
     'tags'  : ["clang"],
     'workernames' : ["systemz-1"],
     'builddir': "clang-s390x-linux-lnt",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     jobs=4,
                     clean=False,
                     checkout_lld=False,
+                    enable_runtimes="auto",
                     useTwoStage=False,
                     runTestSuite=True,
                     stage1_config='Release',
                     testsuite_flags=['--threads=4', '--build-threads=4'],
                     extra_cmake_args=[
                         "-DLLVM_CCACHE_BUILD=ON",
                         "-DLLVM_ENABLE_ASSERTIONS=ON"])},