[sanitizer] Clear clang_build and use ccache
diff --git a/zorg/buildbot/builders/sanitizers/buildbot_cmake.sh b/zorg/buildbot/builders/sanitizers/buildbot_cmake.sh
index 5725ef7..5e609a5 100755
--- a/zorg/buildbot/builders/sanitizers/buildbot_cmake.sh
+++ b/zorg/buildbot/builders/sanitizers/buildbot_cmake.sh
@@ -17,7 +17,14 @@
 export ANDROID_SDK_HOME=$ROOT/../../..
 
 # Always clobber bootstrap build trees.
-rm -rf compiler_rt_build llvm_build64 llvm_build_ninja symbolizer_build*
+rm -rf compiler_rt_build llvm_build* symbolizer_build*
+
+USE_CCACHE=
+if ccache -s ; then
+  USE_CCACHE="-DLLVM_CCACHE_BUILD=ON"
+else
+  rm -rf clang_build
+fi
 
 SUPPORTS_32_BITS=${SUPPORTS_32_BITS:-1}
 MAKE_JOBS=${MAX_MAKE_JOBS:-$(nproc)}
@@ -133,7 +140,7 @@
 if [ ! -d clang_build ]; then
   mkdir clang_build
 fi
-(cd clang_build && cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo ${CMAKE_COMMON_OPTIONS} $LLVM) || echo @@@STEP_FAILURE@@@
+(cd clang_build && cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo ${CMAKE_COMMON_OPTIONS} ${USE_CCACHE} $LLVM) || echo @@@STEP_FAILURE@@@
 
 BOOTSTRAP_BUILD_TARGETS="clang"
 if [[ "$CHECK_LLD" != "0" ]]; then