cmd/internal/obj/wasm: use i64 for large return addr

Use i64 to avoid overflow when getting PC_F from the return addr.

Fixes #73246

Change-Id: I5683dccf7eada4b8536edf53e2e83116a2f6d943
GitHub-Last-Rev: 267d9a1
GitHub-Pull-Request: #73277
Reviewed-on: https://go-review.googlesource.com/c/go/+/663995
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Cherry Mui <[email protected]>

Author: Zxilly

src/cmd/internal/obj/wasm/wasmobj.go

@@ -1006,9 +1006,10 @@ func genWasmExportWrapper(s *obj.LSym, appendp func(p *obj.Prog, as obj.As, args
 	// In the unwinding case, we call wasm_pc_f_loop_export to handle stack switch and rewinding,
 	// until a normal return (non-unwinding) back to this function.
 	p = appendp(p, AIf)
-	p = appendp(p, AI32Const, retAddr)
-	p = appendp(p, AI32Const, constAddr(16))
-	p = appendp(p, AI32ShrU)
+	p = appendp(p, AI64Const, retAddr)
+	p = appendp(p, AI64Const, constAddr(16))
+	p = appendp(p, AI64ShrU)
+	p = appendp(p, AI32WrapI64)
 	p = appendp(p, ACall, obj.Addr{Type: obj.TYPE_MEM, Name: obj.NAME_EXTERN, Sym: wasm_pc_f_loop_export})
 	p = appendp(p, AEnd)