Move impl cycle tests to min-prelude (#5108)

Use the facet_types min-prelude instead of defining a Core package in
the test file.

Author: danakj

toolchain/check/testdata/impl/no_prelude/impl_cycle.carbon renamed to toolchain/check/testdata/impl/lookup/min_prelude/impl_cycle.carbon

@@ -2,38 +2,18 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --no-dump-sem-ir
+// INCLUDE-FILE: toolchain/testing/min_prelude/facet_types.carbon
+// EXTRA-ARGS: --no-dump-sem-ir --custom-core
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/impl_cycle.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/lookup/min_prelude/impl_cycle.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/impl_cycle.carbon
-
-// --- core.carbon
-package Core;
-
-interface As(Dest:! type) {
-  fn Convert[self: Self]() -> Dest;
-}
-
-interface ImplicitAs(Dest:! type) {
-  fn Convert[self: Self]() -> Dest;
-}
-
-interface BitAnd {
-  fn Op[self: Self](other: Self) -> Self;
-}
-
-impl forall [T:! type] T as BitAnd {
-  fn Op[self: Self](other: Self) -> Self = "type.and";
-}
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/lookup/min_prelude/impl_cycle.carbon
 
 // --- fail_impl_simple_cycle.carbon
 library "[[@TEST_NAME]]";
 
-import Core;
-
 interface Z {}
 
 // This creates a dependency cycle with itself.
@@ -57,8 +37,6 @@ fn F() {
 // --- todo_fail_impl_simple_where_cycle.carbon
 library "[[@TEST_NAME]]";
 
-import Core;
-
 interface Z {}
 
 // This creates a dependency cycle with itself.
@@ -76,8 +54,6 @@ fn F() {
 // --- fail_impl_simple_two_interfaces.carbon
 library "[[@TEST_NAME]]";
 
-import Core;
-
 interface Z {}
 interface Y {}
 
@@ -103,8 +79,6 @@ fn F() {
 // --- fail_impl_long_cycle.carbon
 library "[[@TEST_NAME]]";
 
-import Core;
-
 interface X {}
 interface Y {}
 interface Z {}
@@ -137,8 +111,6 @@ fn F() {
 // --- fail_impl_cycle_one_generic_param.carbon
 library "[[@TEST_NAME]]";
 
-import Core;
-
 interface ComparableWith(T:! type) {}
 
 // This creates a dependency cycle with itself.
@@ -208,8 +180,6 @@ fn F() {
 // --- impl_recurse_with_simpler_type_no_cycle.carbon
 library "[[@TEST_NAME]]";
 
-import Core;
-
 class Wraps(T:! type) {}
 
 interface Printable {}
@@ -228,8 +198,6 @@ fn F() {
 // --- impl_recurse_with_simpler_type_in_generic_param_no_cycle.carbon
 library "[[@TEST_NAME]]";
 
-import Core;
-
 class Wraps(T:! type) {}
 
 interface ComparableTo(T:! type) {}
@@ -253,8 +221,6 @@ fn F() {
 // --- impl_recurse_with_simpler_type_in_generic_param_bidirectional_no_cycle.carbon
 library "[[@TEST_NAME]]";
 
-import Core;
-
 // Implement this for a type in one direction.
 interface ComparableTo(T:! type) {}
 // Use this as a bound with two types in any direction.