DUMP_LEAKS misreports memory leak

[bnoordhuis]

$ touch empty.js
$ build/qjs -D0x4000 empty.js
Memory leak: 192 bytes lost in 2 blocks

There is no actual memory leak: the DUMP_LEAKS code runs before the final two js_free_rt calls

[bnoordhuis]

Side note: qjs empty.js calls malloc+free over 1680 times. Lot more than I expected.