Enabling ccache for all ppc64le buildbots

[kamaub]

Summary

This changed turns on the cmake variable that makes buildbots
build with ccache. Its intent is to use ccache to improve the
build times of the PowerPC 64-bit Little Endian buildbots.

[nemanjai]

LGTM. Thanks for fixing this.

[gkistanova]

Thanks, Kamau!
LGTM.

buildbot/osuosl/master/config/builders.py

# Clang builders.
     'builddir': "clang-ppc64le-lnt",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     clean=False,
                     checkout_lld=False,
                     useTwoStage=False,
                     runTestSuite=True,
                     stage1_config='Release',
                     nt_flags=['--threads=16', '--build-threads=16'],
-                    extra_cmake_args=["-DLLVM_ENABLE_ASSERTIONS=ON"])},
+                    extra_cmake_args=[
+                        "-DLLVM_ENABLE_ASSERTIONS=ON",
+                        "-DLLVM_CCACHE_BUILD=ON"])},
 
     {'name' : "clang-ppc64le-linux-multistage",
     'tags'  : ["clang", "ppc", "ppc64le"],
     'workernames' : ["ppc64le-clang-multistage-test"],
     'builddir': "clang-ppc64le-multistage",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     clean=False,
                     checkout_lld=False,
                     useTwoStage=True,
                     stage1_config='Release',
                     stage2_config='Release',
-                    extra_cmake_args=['-DLLVM_ENABLE_ASSERTIONS=ON', '-DBUILD_SHARED_LIBS=ON'])},
+                    extra_cmake_args=[
+                        '-DLLVM_ENABLE_ASSERTIONS=ON',
+                        '-DBUILD_SHARED_LIBS=ON',
+                        '-DLLVM_CCACHE_BUILD=ON'])},
 
     {'name' : "clang-ppc64le-rhel",
     'tags'  : ["clang", "ppc", "ppc64le"],
     'workernames' : ["ppc64le-clang-rhel-test"],
     'builddir': "clang-ppc64le-rhel",
     'factory' : TestSuiteBuilder.getTestSuiteBuildFactory(
                     depends_on_projects=["llvm", "clang", "clang-tools-extra", "lld", "compiler-rt"],
                     checks=["check"],
# LLD builders.
 
     {'name' : "ppc64le-lld-multistage-test",
     'tags'  : ["lld", "ppc", "ppc64le"],
     'workernames' : ["ppc64le-lld-multistage-test"],
     'builddir': "ppc64le-lld-multistage-test",
     'factory' : UnifiedTreeBuilder.getCmakeWithNinjaMultistageBuildFactory(
                     extra_configure_args=[
                         '-DLLVM_ENABLE_ASSERTIONS=ON',
-                        '-DLLVM_LIT_ARGS=-svj 256'],
+                        '-DLLVM_LIT_ARGS=-svj 256',
+                        '-DLLVM_CCACHE_BUILD=ON'],
                     depends_on_projects=['llvm', 'clang', 'lld'])},
 
     {'name' : "lld-x86_64-ubuntu-fast",
     'tags'  : ["lld"],
     'collapseRequests': False,
     'workernames' : ["as-builder-4"],
     'builddir' : "lld-x86_64-ubuntu-fast",
     'factory': UnifiedTreeBuilder.getCmakeWithNinjaBuildFactory(
'factory' : UnifiedTreeBuilder.getCmakeWithNinjaBuildFactory(
                     targets = ['check-mlir-build-only'],
                     checks = ['check-mlir'],
                     extra_configure_args=[
                         '-DLLVM_TARGETS_TO_BUILD=PowerPC',
                         '-DLLVM_INSTALL_UTILS=ON',
                         '-DCMAKE_CXX_STANDARD=17',
                         '-DLLVM_ENABLE_PROJECTS=mlir',
                         '-DLLVM_LIT_ARGS=-vj 256',
+                        '-DLLVM_CCACHE_BUILD=ON',
                     ],
                     env={
                             'CC': 'clang',
                             'CXX': 'clang++',
                             'LD': 'lld',
                             'LD_LIBRARY_PATH': '/usr/lib64',
                     })},
 
# Sanitizer builders.
 
     {'name' : "sanitizer-ppc64le-linux",
     'tags'  : ["sanitizer", "ppc", "ppc64le"],
     'workernames' : ["ppc64le-sanitizer"],
     'builddir': "sanitizer-ppc64le",
     'factory' : SanitizerBuilder.getSanitizerBuildFactory(
                     timeout=1800,
                     extra_configure_args=[
-                       "-CMAKE_ARGS='-DLLVM_LIT_ARGS=-v -j256'"])},
+                       "-CMAKE_ARGS='-DLLVM_LIT_ARGS=-v -j256'",
+                       "-DLLVM_CCACHE_BUILD=ON"])},
 
     {'name' : "sanitizer-windows",
     'tags'  : ["sanitizer"],
     'workernames' : ["sanitizer-windows"],
     'builddir': "sanitizer-windows",
     'factory' : AnnotatedBuilder.getAnnotatedBuildFactory(
                     script="sanitizer-windows.py",
                     depends_on_projects=["llvm", "clang", "lld", "compiler-rt"])},
# Flang builders.
     'factory' : UnifiedTreeBuilder.getCmakeWithNinjaBuildFactory(
                     clean=True,
                     depends_on_projects=['llvm', 'mlir', 'clang', 'flang'],
                     checks=['check-flang'],
                     extra_configure_args=[
                         '-DLLVM_TARGETS_TO_BUILD=PowerPC',
                         '-DLLVM_INSTALL_UTILS=ON',
                         '-DCMAKE_CXX_STANDARD=17',
-                        '-DLLVM_LIT_ARGS=-vj 256'
+                        '-DLLVM_LIT_ARGS=-vj 256',
+                        '-DLLVM_CCACHE_BUILD=ON'
                     ],
                     env={
                         'CC': 'clang',
                         'CXX': 'clang++',
                         'LD': 'lld'
                     })},
 
     {'name' : "flang-x86_64-windows",