Add test that validates swt clone module function references.

tests/c/swt_module_clone.c

@@ -0,0 +1,84 @@
+// ignore-if: test "$YKB_TRACER" != "swt"
+// Run-time:
+//   env-var: YKD_LOG_IR=aot,jit-post-opt,jit-pre-opt
+//   env-var: YKD_SERIALISE_COMPILATION=1
+//   env-var: YK_LOG=4
+//   stderr:
+//     yk-jit-event: start-tracing
+//     4
+//     yk-jit-event: stop-tracing
+//     --- Begin aot ---
+//     ...
+//     func add(%arg0: i32, %arg1: i32) -> i32 {
+//     ...
+//     func dec(%arg0: i32) -> i32 {
+//     ...
+//     %{{_}}: i32 = call add(%{{_}}, -1i32) [safepoint: 2i64, (%{{_}}, %{{_}})]
+//     ...
+//     func main(%arg0: i32, %arg1: ptr) -> i32 {
+//     ...
+//     *%{{_}} = dec
+//     ...
+//     %{{_}}: i32 = icall %{{_}}(%{{_}})
+//     ...
+//     --- End aot ---
+//     --- Begin jit-pre-opt ---
+//     ...
+//     %{{_}}: i32 = icall %{{_}}(%{{_}})
+//     ...
+//     --- End jit-pre-opt ---
+//     --- Begin jit-post-opt ---
+//     ...
+//     %{{_}}: i32 = icall %{{_}}(%{{_}})
+//     ...
+//     --- End jit-post-opt ---
+//     3
+//     yk-jit-event: enter-jit-code
+//     2
+//     1
+//     yk-jit-event: deoptimise
+//     exit
+//   status: success
+
+// Check that functions which address is taken can refer to other
+// functions which address is not taken. This test is specific for SWT
+// with module cloning enabled. Note that the cloned functions will not
+// be visible in the aot ir since they are not serialised.
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <yk.h>
+#include <yk_testing.h>
+
+__attribute__((yk_outline)) int add(int i, int j) { return i + j; }
+
+__attribute__((yk_outline)) int dec(int i) { return add(i, -1); }
+
+int main(int argc, char **argv) {
+  YkMT *mt = yk_mt_new(NULL);
+  yk_mt_hot_threshold_set(mt, 0);
+  YkLocation loc = yk_location_new();
+
+  int res = 9998;
+  int i = 4;
+  NOOPT_VAL(loc);
+  NOOPT_VAL(res);
+  NOOPT_VAL(i);
+
+  // Take a reference to the 'dec' function using a function pointer.
+  // This will cause dec function to not be cloned.
+  int (*dec_ptr)(int) = dec;
+
+  while (i > 0) {
+    yk_mt_control_point(mt, &loc);
+    fprintf(stderr, "%d\n", i);
+    i = dec_ptr(i);
+  }
+  fprintf(stderr, "exit\n");
+  NOOPT_VAL(res);
+  yk_location_drop(loc);
+  yk_mt_shutdown(mt);
+  return (EXIT_SUCCESS);
+}