use indirect return for i128 and f128 on wasm32

Author: folkertdev

compiler/rustc_target/src/callconv/wasm.rs

@@ -1,3 +1,5 @@
+use rustc_abi::{BackendRepr, Float, Integer, Primitive};
+
 use crate::abi::call::{ArgAbi, FnAbi};
 use crate::abi::{HasDataLayout, TyAbiInterface};
 
@@ -27,6 +29,16 @@ where
     if ret.layout.is_aggregate() && !unwrap_trivial_aggregate(cx, ret) {
         ret.make_indirect();
     }
+
+    // `long double`, `__int128_t` and `__uint128_t` use an indirect return
+    if let BackendRepr::Scalar(scalar) = ret.layout.backend_repr {
+        match scalar.primitive() {
+            Primitive::Int(Integer::I128, _) | Primitive::Float(Float::F128) => {
+                ret.make_indirect();
+            }
+            _ => {}
+        }
+    }
 }
 
 fn classify_arg<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>)