ucode: update to latest Git HEAD

ucode: update to latest Git HEAD

aa9621d compiler: rework switch statement code generation
b5f0de1 vm: add trace mode instruction dump output fixes
0341d64 vm: fix another for-loop memory leak
00d9419 vm: fix further memory leaks in trace mode
20a3763 vm: fix loop variable memory leak in NEXTK/NEXTKV instruction
9a6ef2b lib: prevent use-after-free after uc_shift()
03f1324 object: free prototype object when registering existing ressource type
b3d758b compiler: fix for/break miscompilation
86e3970 lib: fix value refcount of uc_unshift() return value
fe464ea run_tests.sh: allow passing tests to run as arguments
091ae1b compiler: fix another try/catch miscompilation
fcedb19 lib: fix passing uninitialized memory to sigprocmask()
0d0357d vm: fix leaking source context strings in trace mode
7a41fb3 lib: use execvp() in system()

Signed-off-by: Jo-Philipp Wich <jo@mein.io>