Fixes for elf_aux_info support

- Remove the unnecessary use of the sys/elf.h header

- Add RISC-V support

configure.ac

@@ -221,9 +221,9 @@ fi
 # additional checks for RVV targets
 if test x$check_for_rvv = x1; then
   AC_MSG_NOTICE([checking how to detect RVV availability])
-  AC_CHECK_FUNCS([getauxval])
+  AC_CHECK_FUNCS([getauxval elf_aux_info])
 
-  if test $ac_cv_func_getauxval = no; then
+  if test $ac_cv_func_getauxval = no && test $ac_cv_func_elf_aux_info = no; then
       AC_MSG_WARN([RVV is available, but we don't know how to check for it.  Will not be able to use RVV.])
   fi
 fi

src/arch/simddetect.cpp

@@ -61,12 +61,11 @@
 #    include <sys/auxv.h>
 #  elif defined(HAVE_ELF_AUX_INFO)
 #    include <sys/auxv.h>
-#    include <sys/elf.h>
 #  endif
 #endif
 
 #if defined(HAVE_RVV)
-#  if defined(HAVE_GETAUXVAL)
+#  if defined(HAVE_GETAUXVAL) || defined(HAVE_ELF_AUX_INFO)
 #    include <sys/auxv.h>
 #    define HWCAP_RV(letter) (1ul << ((letter) - 'A'))
 #  endif
@@ -244,6 +243,10 @@ SIMDDetect::SIMDDetect() {
 #  if defined(HAVE_GETAUXVAL)
   const unsigned long hwcap = getauxval(AT_HWCAP);
   rvv_available_ = hwcap & HWCAP_RV('V');
+#  elif defined(HAVE_ELF_AUX_INFO)
+  unsigned long hwcap = 0;
+  elf_aux_info(AT_HWCAP, &hwcap, sizeof hwcap);
+  rvv_available_ = hwcap & HWCAP_RV('V');
 #  endif
 #endif