Variables starting with `s' in makedefs

• s makedefs/MakeInc.rule:346
• setup_build_install makedefs/MakeInc.dir:377
• setup_subdir makedefs/MakeInc.dir:223
• SETUP_SUBDIRS_ makedefs/MakeInc.dir:241
• SOURCE makedefs/MakeInc.dir:34
• space makedefs/MakeInc.def:190
• SRCROOT makedefs/MakeInc.dir:269
• strip makedefs/MakeInc.rule:36
• subst makedefs/MakeInc.def:32