Fuzz JSPI (#7148)

* Add a new "sleep" fuzzer import, that does a sleep for some ms.

* Add JSPI support in fuzz_shell.js. This is in the form of commented-out async/await
   keywords - commented out so that normal fuzzing is not impacted. When we want
   to fuzz JSPI, we uncomment them. We also apply the JSPI operations of marking
   imports and exports as suspending/promising.
   JSPI fuzzing is added to both fuzz_opt.py and ClusterFuzz's run.py.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/tools/execution-results.h b/src/tools/execution-results.h
index b8823c3f0..ea822d547 100644
--- a/src/tools/execution-results.h
+++ b/src/tools/execution-results.h
@@ -128,6 +128,9 @@ public:
         } catch (const WasmException& e) {
           return {Literal(int32_t(1))};
         }
+      } else if (import->base == "sleep") {
+        // Do not actually sleep, just return the id.
+        return {arguments[1]};
       } else {
         WASM_UNREACHABLE("unknown fuzzer import");
       }