add u128/i128 to sum/product implementors

Resolves #43235.

Author: zackmdavis

src/libcore/iter/traits.rs

@@ -732,7 +732,7 @@ macro_rules! float_sum_product {
     )*)
 }
 
-integer_sum_product! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize }
+integer_sum_product! { i8 i16 i32 i64 i128 isize u8 u16 u32 u64 u128 usize }
 float_sum_product! { f32 f64 }
 
 /// An iterator adapter that produces output as long as the underlying

src/test/run-pass/i128.rs

@@ -109,4 +109,8 @@ fn main() {
     assert_eq!(b(-87559967289969187895646876466835277875_i128) /
                b(84285771033834995895337664386045050880_i128),
                -1i128);
+
+    // iter-arithmetic traits
+    assert_eq!(10i128, [1i128, 2, 3, 4].iter().sum());
+    assert_eq!(24i128, [1i128, 2, 3, 4].iter().product());
 }

src/test/run-pass/u128.rs

@@ -122,4 +122,8 @@ fn main() {
     assert_eq!(b(0x679289ac23bb334f_36144401cf882172_u128) /
                b(0x7b0b271b64865f05_f54a7b72746c062f_u128),
                0u128);
+
+    // iter-arithmetic traits
+    assert_eq!(10u128, [1u128, 2, 3, 4].iter().sum());
+    assert_eq!(24u128, [1u128, 2, 3, 4].iter().product());
 }