wasm: fix size of pointers in structs (#26357)

Author: SurmanPP

vlib/v/gen/wasm/serialise/serialise.v

@@ -58,6 +58,10 @@ pub fn (mut p Pool) type_struct_info(typ ast.Type) ?StructInfo {
 }
 
 pub fn (mut p Pool) type_size(typ ast.Type) (int, int) {
+	if typ.nr_muls() > 0 {
+		return p.table.pointer_size, p.table.pointer_size
+	}
+
 	ts := p.table.sym(typ)
 	if ts.size != -1 && typ.idx() in p.structs {
 		return ts.size, ts.align

vlib/v/gen/wasm/tests/misc.vv

@@ -82,7 +82,24 @@ fn run_defer() {
 	defer_if(false)
 }
 
+struct HasPointers {
+	a   int
+	msg &string
+pub mut:
+	same &HasPointers
+}
+
+fn ptr_in_struct() {
+	msg := 'pointer in struct'
+	mut s := HasPointers{1234, &msg, unsafe { nil }}
+	println(*s.msg)
+	s.same = &s
+	println(*&int(voidptr(s.same.a))) // FIXME: wont work without casts
+}
+
 fn main() {
+	println('ptr_in_struct')
+	ptr_in_struct()
 	println('ptr_arith')
 	ptr_arith()
 	run_defer()

vlib/v/gen/wasm/tests/misc.vv.out

@@ -1,3 +1,6 @@
+ptr_in_struct
+pointer in struct
+1234
 ptr_arith
 12
 14