[configure][bug-fix] Add existence check for compiler

Issue: #1023

Add a configure test that verifies the presence of the compiler
before we continue on using it in the following tests. If missing
return an indicative error to the user.

Signed-off-by: Eyal Itkin <eyal.itkin@gmail.com>

configure

@@ -184,6 +184,14 @@ else
   cc=${CC}
 fi
 
+echo "Checking for compiler existence" >> configure.log
+if which $cc >/dev/null 2>&1; then
+  :
+else
+  echo "Failed to find an installed compiler." | tee -a configure.log
+  leave 1
+fi
+
 case "$cc" in
   *gcc*) gcc=1 ;;
   *clang*) gcc=1 ;;