Fixup update hpcombi

Makefile.am

@@ -12,6 +12,10 @@ if LIBSEMIGROUPS_HPCOMBI_ENABLED
 AM_CXXFLAGS += $(HPCOMBI_CXXFLAGS)
 AM_CXXFLAGS += -I$(abs_top_srcdir)/extern/HPCombi/include
 AM_CXXFLAGS += -I$(abs_top_srcdir)/extern/HPCombi/third_party
+# The next line is there to avoid warnings about "-mavx" being unused. This
+# flag apparently exists in clang even on systems that don't implement the AVX
+# instruction set (such as apple clang version 14.0.3)
+AM_CXXFLAGS += -Wno-unused-command-line-argument
 endif
 
 AM_LDFLAGS  =  -no-undefined -lpthread $(FMT_LIBS)
@@ -132,6 +136,7 @@ backwardcppinclude_HEADERS=extern/backward-cpp/backward.hpp
 ## LIBSEMIGROUPS_HPCOMBI_ENABLED because it is used by
 ## uninstall-hook
 hpcombiincludedir = $(includedir)/libsemigroups/hpcombi
+simdeincludedir = $(includedir)/libsemigroups/hpcombi/simde/x86
 if LIBSEMIGROUPS_HPCOMBI_ENABLED
 hpcombiinclude_HEADERS =  extern/HPCombi/include/hpcombi/arch.hpp
 hpcombiinclude_HEADERS += extern/HPCombi/include/hpcombi/bmat8.hpp
@@ -149,6 +154,9 @@ hpcombiinclude_HEADERS += extern/HPCombi/include/hpcombi/power.hpp
 hpcombiinclude_HEADERS += extern/HPCombi/include/hpcombi/vect16.hpp
 hpcombiinclude_HEADERS += extern/HPCombi/include/hpcombi/vect_generic.hpp
 
+simdeinclude_HEADERS = extern/HPCombi/third_party/simde/x86/sse4.1.h
+simdeinclude_HEADERS += extern/HPCombi/third_party/simde/x86/sse4.2.h
+
 endif ## LIBSEMIGROUPS_HPCOMBI_ENABLED
 
 ## Define fmtincludedir outside the conditional

m4/ax_check_hpcombi.m4

@@ -24,7 +24,8 @@ AS_IF([test "x$enable_hpcombi" = xyes],
 
 AS_IF([test "x$enable_hpcombi" = xyes], 
       [AX_CHECK_COMPILE_FLAG(-flax-vector-conversions, 
-                             AX_APPEND_FLAG(-flax-vector-conversions, [ax_hpcombi_cxxflags_variable]),
+                             AX_APPEND_FLAG(-flax-vector-conversions, 
+                             [ax_hpcombi_cxxflags_variable]),
                              [])])
 
 # TODO check if compiling in 32-bit, and in that case disable hpcombi