[test-release.sh] Do not run chrpath on AIX.

[amyk]

Summary

Upon testing the use of test-release.sh on AIX, the script initially fails because chrpath
is not present on AIX. This patch adds checks for AIX and allows the script to continue
running to completion.

llvm/utils/release/test-release.sh

 function check_program_exists() {
   local program="$1"
   if ! type -P $program > /dev/null 2>&1 ; then
     echo "program '$1' not found !"
     exit 1
   fi
 }
 
-if [ "$System" != "Darwin" -a "$System" != "SunOS" ]; then
+if [ "$System" != "Darwin" ] && [ "$System" != "SunOS" ] && [ "$System" != "AIX" ]; then
   check_program_exists 'chrpath'
 fi
 
 if [ "$System" != "Darwin" ]; then
   check_program_exists 'file'
   check_program_exists 'objdump'
 fi
 
if [ $do_test_suite = 'yes' ]; then
       fi
     fi
     cd $BuildDir
 }
 
 # Clean RPATH. Libtool adds the build directory to the search path, which is
 # not necessary --- and even harmful --- for the binary packages we release.
 function clean_RPATH() {
-  if [ "$System" = "Darwin" -o "$System" = "SunOS" ]; then
+  if [ "$System" = "Darwin" ] || [ "$System" = "SunOS" ] || [ "$System" = "AIX" ]; then
     return
   fi
   local InstallPath="$1"
   for Candidate in `find $InstallPath/{bin,lib} -type f`; do
     if file $Candidate | grep ELF | egrep 'executable|shared object' > /dev/null 2>&1 ; then
       if rpath=`objdump -x $Candidate | grep 'RPATH'` ; then
         rpath=`echo $rpath | sed -e's/^ *RPATH *//'`
         if [ -n "$rpath" ]; then