Add i64 tests to IsubBorrow and move tests.

Copyright (c) 2021, Arm Limited

cranelift/filetests/filetests/runtests/isubborrow.clif

@@ -70,4 +70,29 @@ block0(v0: i32, v1: i32, v2: b1):
 ; run: %isubborrow_i32_c(100, 20, true) == false
 ; run: %isubborrow_i32_c(100, 20, false) == false
 ; run: %isubborrow_i32_c(-2147483640, 8, true) == true
-; run: %isubborrow_i32_c(-2147483640, 8, false) == true
+; run: %isubborrow_i32_c(-2147483640, 8, false) == true
+
+
+function %isubborrow_i64_v(i64, i64, b1) -> i64 {
+block0(v0: i64, v1: i64, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v3
+}
+; run: %isubborrow_i64_v(0, 1, true) == -2
+; run: %isubborrow_i64_v(0, 1, false) == -1
+; run: %isubborrow_i64_v(100, 20, true) == 79
+; run: %isubborrow_i64_v(100, 20, false) == 80
+; run: %isubborrow_i64_v(-9223372036854775800, 8, true) == 9223372036854775807
+; run: %isubborrow_i64_v(-9223372036854775800, 8, false) == -9223372036854775808
+
+function %isubborrow_i64_c(i64, i64, b1) -> b1 {
+block0(v0: i64, v1: i64, v2: b1):
+    v3, v4 = isub_borrow v0, v1, v2
+    return v4
+}
+; run: %isubborrow_i64_c(0, 1, true) == true
+; run: %isubborrow_i64_c(0, 1, false) == true
+; run: %isubborrow_i64_c(100, 20, true) == false
+; run: %isubborrow_i64_c(100, 20, false) == false
+; run: %isubborrow_i64_c(-9223372036854775800, 8, true) == true
+; run: %isubborrow_i64_c(-9223372036854775800, 8, false) == true