Preserve JIT shim object during PGO clean

Author: diegorusso

Makefile.pre.in

@@ -3226,9 +3226,7 @@ $(JIT_GENERATED_STAMP): $(JIT_DEPS)
 	@REGEN_JIT_COMMAND@
 	@touch $@
 
-# The stamp regenerates all JIT outputs as a group. Keep it order-only so its
-# newer timestamp does not make each generated artifact look stale.
-$(JIT_BUILD_TARGETS): | $(JIT_GENERATED_STAMP)
+$(JIT_BUILD_TARGETS): $(JIT_GENERATED_STAMP)
 	@if test ! -f "$@"; then \
 		rm -f $(JIT_GENERATED_STAMP); \
 		$(MAKE) $(JIT_GENERATED_STAMP); \
@@ -3325,7 +3323,9 @@ docclean:
 # data.  The PGO data is only valid if source code remains unchanged.
 .PHONY: clean-retain-profile
 clean-retain-profile: pycremoval
-	find . -name '*.[oa]' -exec rm -f {} ';'
+	# Keep the generated JIT shim objects with the rest of the JIT generated
+	# files: they are regenerated as a group and tracked by .jit-stamp.
+	find . -name '*.[oa]' ! -name 'jit_shim*.o' -exec rm -f {} ';'
 	find . -name '*.s[ol]' -exec rm -f {} ';'
 	find . -name '*.so.[0-9]*.[0-9]*' -exec rm -f {} ';'
 	find . -name '*.lto' -exec rm -f {} ';'