some optimizations

Rev: src/global.h:1.22
Rev: src/interpret.c:1.81
Rev: src/language.yacc:1.96
Rev: src/las.c:1.62
Rev: src/lex.c:1.53
Rev: src/peep.c:1.24
Rev: src/peep.in:1.15
Rev: src/testsuite.in:1.105