tests/bench/runtime_coreapis: disable test with LLVM

This triggers a known bug much more often than with gnu toolchains to
the point that merging this PR without disabling the test would
render the CI useless.

tests/bench/runtime_coreapis/Makefile

@@ -4,4 +4,10 @@ include ../Makefile.bench_common
 USEMODULE += core_thread_flags
 USEMODULE += benchmark
 
+ifeq (llvm,$(TOOLCHAIN))
+  # the floating point exception bug is more likely to trigger when build
+  # with LLVM, so we just disable LLVM on native as a work around
+  TEST_ON_CI_BLACKLIST += native
+endif
+
 include $(RIOTBASE)/Makefile.include