Add sign extension tests

Author: abelstuker

tests/latch/core/i32_0.asserts.wast

@@ -198,9 +198,13 @@
        (assert_return (invoke "popcnt" (i32.const 0xDEADBEEF)) (i32.const 24))
        (assert_return (invoke "extend8_s" (i32.const 0)) (i32.const 0))
        (assert_return (invoke "extend8_s" (i32.const 0x7f)) (i32.const 127))
+       (assert_return (invoke "extend8_s" (i32.const 0x80)) (i32.const -128))
+       (assert_return (invoke "extend8_s" (i32.const 0xff)) (i32.const -1))
        (assert_return (invoke "extend8_s" (i32.const -1)) (i32.const -1))
        (assert_return (invoke "extend16_s" (i32.const 0)) (i32.const 0))
        (assert_return (invoke "extend16_s" (i32.const 0x7fff)) (i32.const 32767))
+       (assert_return (invoke "extend16_s" (i32.const 0x8000)) (i32.const -32768))
+       (assert_return (invoke "extend16_s" (i32.const 0xffff)) (i32.const -1))
        (assert_return (invoke "extend16_s" (i32.const -1)) (i32.const -1))
        (assert_return (invoke "eqz" (i32.const 0)) (i32.const 1))
        (assert_return (invoke "eqz" (i32.const 1)) (i32.const 0))

tests/latch/core/i64_0.asserts.wast

@@ -131,9 +131,13 @@
        (assert_return (invoke "popcnt" (i64.const 0x00008000)) (i64.const 1))
        (assert_return (invoke "extend8_s" (i64.const 0)) (i64.const 0))
        (assert_return (invoke "extend8_s" (i64.const 0x7f)) (i64.const 127))
+       (assert_return (invoke "extend8_s" (i64.const 0x80)) (i64.const -128))
+       (assert_return (invoke "extend8_s" (i64.const 0xff)) (i64.const -1))
        (assert_return (invoke "extend8_s" (i64.const -1)) (i64.const -1))
        (assert_return (invoke "extend16_s" (i64.const 0)) (i64.const 0))
        (assert_return (invoke "extend16_s" (i64.const 0x7fff)) (i64.const 32767))
+       (assert_return (invoke "extend16_s" (i64.const 0x8000)) (i64.const -32768))
+       (assert_return (invoke "extend16_s" (i64.const 0xffff)) (i64.const -1))
        (assert_return (invoke "extend16_s" (i64.const -1)) (i64.const -1))
        (assert_return (invoke "extend32_s" (i64.const 0)) (i64.const 0))
        (assert_return (invoke "extend32_s" (i64.const 0x7fff)) (i64.const 32767))