JIT compile getsignals

Although this probably isn't likely to be part of any hot code path,
adding JIT support for the getsignals op.

src/jit/core_templates.expr

@@ -818,6 +818,11 @@
       (carg $3 ptr)
       (carg $5 int_sz)) ptr_sz))
 
+(template: getsignals
+  (call (^func &MVM_io_get_signals)
+    (arglist
+      (carg (tc) ptr)) ptr_sz))
+
 (template: slice!
   (let: (
     ($dest (call (^getf (^repr $1) MVMREPROps allocate)

src/jit/graph.c

@@ -324,6 +324,7 @@ static void * op_to_func(MVMThreadContext *tc, MVMint16 opcode) {
     case MVM_OP_decont_s: return MVM_6model_container_decont_s;
     case MVM_OP_getrusage: return MVM_proc_getrusage;
     case MVM_OP_cpucores: return MVM_platform_cpu_count;
+    case MVM_OP_getsignals: return MVM_io_get_signals;
     case MVM_OP_sleep: return MVM_platform_sleep;
     case MVM_OP_getlexref_i32: case MVM_OP_getlexref_i16: case MVM_OP_getlexref_i8: case MVM_OP_getlexref_i: return MVM_nativeref_lex_i;
     case MVM_OP_getlexref_n32: case MVM_OP_getlexref_n: return MVM_nativeref_lex_n;
@@ -3104,6 +3105,12 @@ static MVMint32 consume_ins(MVMThreadContext *tc, MVMJitGraph *jg,
         jg_append_call_c(tc, jg, op_to_func(tc, op), 0, NULL, MVM_JIT_RV_INT, dst);
         break;
     }
+    case MVM_OP_getsignals: {
+        MVMint16 dst = ins->operands[0].reg.orig;
+        MVMJitCallArg args[] =  { { MVM_JIT_INTERP_VAR, { MVM_JIT_INTERP_TC } } };
+        jg_append_call_c(tc, jg, op_to_func(tc, op), 1, args, MVM_JIT_RV_PTR, dst);
+        break;
+    }
     case MVM_OP_sleep: {
         MVMint16 time = ins->operands[0].reg.orig;
         MVMJitCallArg block_args[] = { { MVM_JIT_INTERP_VAR, { MVM_JIT_INTERP_TC } } };