Fix perf-tests.sh to skip building non-upb tests.

Makefile

@@ -295,6 +295,10 @@ BENCHMARKS=$(UPB_BENCHMARKS) \
 
 upb_benchmarks: $(UPB_BENCHMARKS)
 benchmarks: $(BENCHMARKS)
+upb_benchmark: $(UPB_BENCHMARKS)
+	@rm -f benchmarks/results
+	@rm -rf benchmarks/*.dSYM
+	@for test in benchmarks/b.* ; do ./$$test ; done
 benchmark: $(BENCHMARKS)
 	@rm -f benchmarks/results
 	@rm -rf benchmarks/*.dSYM

perf-tests.sh

@@ -18,7 +18,7 @@ run_with_flags () {
   make clean
   echo "$FLAGS" > perf-cppflags
   make upb_benchmarks
-  make benchmark | sed -e "s/^/$NAME./g" | tee -a perf-tests.out
+  make upb_benchmark | sed -e "s/^/$NAME./g" | tee -a perf-tests.out
 }
 
 #if [ x`uname -m` = xx86_64 ]; then