Quote RESCRIPT_BSC_EXE properly

Author: cknitt

rewatch/tests/get_bin_paths.js

@@ -1,4 +1,4 @@
 // @ts-check
 import { bsc_exe } from '../../cli/common/bins.js';
 
-console.log(`RESCRIPT_BSC_EXE=${bsc_exe}`);
+console.log(`RESCRIPT_BSC_EXE='${bsc_exe}'`);