8243470: [macos] bring back O2 opt level for unsafe.cpp

Remove special case for unsafe.cpp on clang macos

Reviewed-by: erikj, ihse

make/hotspot/lib/JvmOverrideFiles.gmk

@@ -92,9 +92,6 @@ else ifeq ($(call isTargetOs, macosx), true)
     # NOTE: The old build tested clang version to make sure this workaround
     # for the clang bug was still needed.
     BUILD_LIBJVM_loopTransform.cpp_CXXFLAGS := $(CXX_O_FLAG_NONE)
-    ifneq ($(DEBUG_LEVEL), slowdebug)
-      BUILD_LIBJVM_unsafe.cpp_CXXFLAGS := -O1
-    endif
 
     # The following files are compiled at various optimization
     # levels due to optimization issues encountered at the
@@ -110,7 +107,6 @@ else ifeq ($(call isTargetOs, macosx), true)
         sharedRuntimeTrig.cpp \
         sharedRuntimeTrans.cpp \
         loopTransform.cpp \
-        unsafe.cpp \
         jvmciCompilerToVM.cpp \
         $(OPT_SPEED_SRC) \
         #