Index: compiler-rt/test/CMakeLists.txt
===================================================================
--- compiler-rt/test/CMakeLists.txt
+++ compiler-rt/test/CMakeLists.txt
@@ -1,6 +1,7 @@
 # Needed for lit support in standalone builds.
 include(AddLLVM)
 
+pythonize_bool(LLVM_ENABLE_EXPENSIVE_CHECKS)
 configure_compiler_rt_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.common.configured.in
   ${CMAKE_CURRENT_BINARY_DIR}/lit.common.configured)
Index: compiler-rt/test/fuzzer/large.test
===================================================================
--- compiler-rt/test/fuzzer/large.test
+++ compiler-rt/test/fuzzer/large.test
@@ -1,3 +1,5 @@
+UNSUPPORTED: expensive_checks
+
 RUN: %cpp_compiler %S/LargeTest.cpp -o %t-LargeTest
 RUN: %run %t-LargeTest -runs=10000
 
Index: compiler-rt/test/lit.common.cfg.py
===================================================================
--- compiler-rt/test/lit.common.cfg.py
+++ compiler-rt/test/lit.common.cfg.py
@@ -477,6 +477,9 @@
 else:
   config.available_features.add("shadow-scale-3")
 
+if config.expensive_checks:
+  config.available_features.add("expensive_checks")
+
 # Propagate the LLD/LTO into the clang config option, so nothing else is needed.
 run_wrapper = []
 target_cflags = [getattr(config, 'target_cflags', None)]
Index: compiler-rt/test/lit.common.configured.in
===================================================================
--- compiler-rt/test/lit.common.configured.in
+++ compiler-rt/test/lit.common.configured.in
@@ -42,6 +42,7 @@
 set_default("android_files_to_push", [])
 set_default("have_rpc_xdr_h", @HAVE_RPC_XDR_H@)
 set_default("gwp_asan", @COMPILER_RT_HAS_GWP_ASAN_PYBOOL@)
+set_default("expensive_checks", @LLVM_ENABLE_EXPENSIVE_CHECKS_PYBOOL@)
 config.available_features.add('target-is-%s' % config.target_arch)
 
 if config.enable_per_target_runtime_dir:
Index: llvm/cmake/modules/LLVMConfig.cmake.in
===================================================================
--- llvm/cmake/modules/LLVMConfig.cmake.in
+++ llvm/cmake/modules/LLVMConfig.cmake.in
@@ -35,6 +35,8 @@
 
 set(LLVM_ABI_BREAKING_CHECKS @LLVM_ABI_BREAKING_CHECKS@)
 
+set(LLVM_ENABLE_EXPENSIVE_CHECKS @LLVM_ENABLE_EXPENSIVE_CHECKS@)
+
 set(LLVM_ENABLE_ASSERTIONS @LLVM_ENABLE_ASSERTIONS@)
 
 set(LLVM_ENABLE_EH @LLVM_ENABLE_EH@)