common: simplify set_common_vars, rename to common_setup

Don't pass all arguments explicitly, just use existing vars.

Prefix all common_setup inputs and outputs with common_ to avoid name conflicts.

rungdb

@@ -14,7 +14,7 @@ while getopts A:a:b:CgkL:n:X OPT; do
       after="$OPTARG"
       ;;
     a)
-      arch="$OPTARG"
+      common_arch="$OPTARG"
       ;;
     b)
       before="$OPTARG"
@@ -24,7 +24,7 @@ while getopts A:a:b:CgkL:n:X OPT; do
       docontinue=false
       ;;
     g)
-      gem5=true
+      common_gem5=true
       ;;
     k)
       kgdb=true
@@ -51,8 +51,8 @@ if [ "$#" -gt 0 ]; then
 else
   brk=
 fi
-set_common_vars -L "$common_linux_variant" -n "$common_run_id" "$arch" "$gem5"
-gdb="${host_dir}/usr/bin/${arch}-linux-gdb \\
+common_setup
+gdb="${common_host_dir}/usr/bin/${common_arch}-linux-gdb \\
 ${before}"
 if "$kgdb"; then
     cmd="\
@@ -98,5 +98,5 @@ if "$docontinue"; then
 ${lx_symbols} \
 "
 fi
-"${root_dir}/eeval" "cd '${common_linux_variant_dir}' && \\
+"${common_root_dir}/eeval" "cd '${common_linux_variant_dir}' && \\
 $cmd $after" "${common_run_dir}/rungdb.sh"