misc/wasm: ensure correct stack pointer in catch clauses

The stack pointer may have changed after a call from JavaScript into Go
code because of stack growth. The normal case already updated the
sp variable accordingly, but the catch case did not yet.

Fixes #45433

Change-Id: I3e0a33381929626f6b21902948935eb5ffb26c96
Reviewed-on: https://go-review.googlesource.com/c/go/+/321936
Trust: Richard Musiol <neelance@gmail.com>
Run-TryBot: Richard Musiol <neelance@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>

misc/wasm/wasm_exec.js

diff --git a/misc/wasm/wasm_exec.js b/misc/wasm/wasm_exec.js
index 3e41e62..231185a 100644
--- a/misc/wasm/wasm_exec.js
+++ b/misc/wasm/wasm_exec.js
@@ -401,6 +401,7 @@
 							storeValue(sp + 56, result);
 							this.mem.setUint8(sp + 64, 1);
 						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
 							storeValue(sp + 56, err);
 							this.mem.setUint8(sp + 64, 0);
 						}
@@ -417,6 +418,7 @@
 							storeValue(sp + 40, result);
 							this.mem.setUint8(sp + 48, 1);
 						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
 							storeValue(sp + 40, err);
 							this.mem.setUint8(sp + 48, 0);
 						}
@@ -433,6 +435,7 @@
 							storeValue(sp + 40, result);
 							this.mem.setUint8(sp + 48, 1);
 						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
 							storeValue(sp + 40, err);
 							this.mem.setUint8(sp + 48, 0);
 						}