[linux-kernel] Update patches for v2

* Reduce stack usage of many zstd functions, none use over 388 B anymore.
* Remove an incorrect `const` in `xxhash`.

contrib/linux-kernel/test/Makefile

@@ -5,21 +5,21 @@ SOURCES := $(wildcard ../lib/zstd/*.c)
 OBJECTS := $(patsubst %.c,%.o,$(SOURCES))
 
 ARFLAGS := rcs
-CXXFLAGS += -std=c++11
-CFLAGS += -g -O0
+CXXFLAGS += -std=c++11 -g -O3 -Wcast-align
+CFLAGS += -g -O3 -Wframe-larger-than=400 -Wcast-align
 CPPFLAGS += $(IFLAGS)
 
 ../lib/zstd/libzstd.a: $(OBJECTS)
 	$(AR) $(ARFLAGS) $@ $^
 
 DecompressCrash: DecompressCrash.o $(OBJECTS) libFuzzer.a
-	$(CXX) $(TEST_CPPFLAGS) $(TEST_CXXFLAGS) $(LDFLAGS) $^ -o $@
+	$(CXX) $(CPPFLAGS) $(CXXFLAGS) $(LDFLAGS) $^ -o $@
 
 RoundTripCrash: RoundTripCrash.o $(OBJECTS) ../lib/xxhash.o libFuzzer.a
-	$(CXX) $(TEST_CPPFLAGS) $(TEST_CXXFLAGS) $(LDFLAGS) $^ -o $@
+	$(CXX) $(CPPFLAGS) $(CXXFLAGS) $(LDFLAGS) $^ -o $@
 
 UserlandTest: UserlandTest.cpp ../lib/zstd/libzstd.a ../lib/xxhash.o
-	$(CXX) $(CXXFLAGS) $(CFLAGS) $(CPPFLAGS) $^ googletest/build/googlemock/gtest/libgtest.a googletest/build/googlemock/gtest/libgtest_main.a -o $@
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) $^ googletest/build/googlemock/gtest/libgtest.a googletest/build/googlemock/gtest/libgtest_main.a -o $@
 
 XXHashUserlandTest: XXHashUserlandTest.cpp ../lib/xxhash.o ../../../lib/common/xxhash.o
 	$(CXX) $(CXXFLAGS) $(CFLAGS) $(CPPFLAGS) $^ googletest/build/googlemock/gtest/libgtest.a googletest/build/googlemock/gtest/libgtest_main.a -o $@
@@ -39,5 +39,5 @@ googletest:
 	@cd googletest/build && cmake .. && $(MAKE)
 
 clean:
-	$(RM) -f *.{o,a} ../lib/zstd/*.{o,a}
+	$(RM) -f *.{o,a} ../lib/zstd/*.{o,a} ../lib/*.o
 	$(RM) -f DecompressCrash RoundTripCrash UserlandTest XXHashUserlandTest