Add warnOnWarnings AnnotatedBuilder property

[Amir]

Summary

Propagate warning status from AnnotatedBuilder step to the full build:
https://docs.buildbot.net/latest/manual/configuration/steps/common.html#buildstep-common-parameters

Use that in bolt-nfc builder where nfc-check-bolt step may report
a warning signifying a mismatch.

[gkistanova]

LGTM.

buildbot/osuosl/master/config/builders.py

# Builders for ML-driven compiler optimizations.
     {'name' : 'bolt-x86_64-ubuntu-nfc',
     'tags'  : ["bolt"],
     'collapseRequests': False,
     'workernames' : ['bolt-worker'],
     'builddir': "bolt-x86_64-ubuntu-nfc",
     'factory' : AnnotatedBuilder.getAnnotatedBuildFactory(
                     script="bolt-nfc.py",
                     depends_on_projects=['llvm', 'bolt'],
+                    warnOnWarnings=True,
                     )},
 
     {'name': "bolt-x86_64-ubuntu-clang-bolt-lto-pgo",
     'tags': ["bolt"],
     'collapseRequests': False,
     'workernames':["bolt-worker"],
     'builddir': "bolt-x86_64-ubuntu-clang-bolt-lto-pgo",
     'factory' : BOLTBuilder.getBOLTCmakeBuildFactory(

zorg/buildbot/builders/AnnotatedBuilder.py

 from buildbot.process.properties import WithProperties
 from buildbot.steps.shell import SetProperty
 from zorg.buildbot.commands.AnnotatedCommand import AnnotatedCommand
 from zorg.buildbot.process.factory import LLVMBuildFactory
 
 
 def getAnnotatedBuildFactory(
     script,
     clean=False,
     depends_on_projects=None,
     env=None,
     extra_args=None,
     timeout=1200,
     checkout_llvm_sources=True,
-    script_interpreter="python"):
+    script_interpreter="python",
+    warnOnWarnings=False):
     """
     Returns a new build factory that uses AnnotatedCommand, which
     allows the build to be run by version-controlled scripts that do
     not require a buildmaster restart to update.
 
     script: script under "builders/annotated" to be run by python
     clean: set to true for a clean build of llvm
     depends_on_projects: which subprojects to enable
else:
         command = [script_path]
 
     command += extra_args_with_props
 
     f.addStep(AnnotatedCommand(name="annotate",
                                description="annotate",
                                timeout=timeout,
                                haltOnFailure=True,
+                               warnOnWarnings=warnOnWarnings,
                                command=command,
                                env=merged_env))
     return f