Add nested array size deduction from tuple (#2909)

As a follow up to #2825 this pr implements size deduction for nested
arrays.
E.g. `var x: [[i32;];] = ((1,2), (3,4));`.

Also updated the pattern matching logic for arrays, now it also checks
element types of the tuple size being deduced from. As a result code
like `var x: [i32;] = ("foo", "bar");`(note, that it tries to init an
array of i32 with a tuple of strings) fails to compile with a pattern
match error instead of an implicit cast failed error.

Moved some common type-related logic used in type_checker.cpp and
interpreter.cpp to the separate file.

explorer/testdata/array/fail_to_deduce_nested_array_size_from_tuple_different_subtuples_size.carbon

@@ -0,0 +1,14 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  // CHECK:STDERR: COMPILATION ERROR: fail_to_deduce_nested_array_size_from_tuple_different_subtuples_size.carbon:[[@LINE+1]]: type pattern '{{\[\[}}i32;];]' does not match actual type '((i32, i32), (i32, i32, i32))'
+  var x: [[i32;];] = ((1,2), (3,4,5));
+
+  return x[0][2];
+}

explorer/testdata/array/fail_to_deduce_nested_array_size_from_tuple_of_different_types.carbon

@@ -0,0 +1,13 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  // CHECK:STDERR: COMPILATION ERROR: fail_to_deduce_nested_array_size_from_tuple_of_different_types.carbon:[[@LINE+1]]: type pattern '{{\[\[}}i32;]; 2]' does not match actual type '((i32, i32), (String, String))'
+  var x: [[i32;];2] = ((1,2), ("foo", "bar"));
+  return x[0];
+}

explorer/testdata/array/fail_to_deduce_size_from_tuple_of_different_types.carbon

@@ -0,0 +1,13 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  // CHECK:STDERR: COMPILATION ERROR: fail_to_deduce_size_from_tuple_of_different_types.carbon:[[@LINE+1]]: type pattern '[i32;]' does not match actual type '(i32, String)'
+  var x: [i32;] = (42, "foo");
+  return x[0];
+}

explorer/testdata/array/fail_to_index_deduced_nested_size_from_array.carbon

@@ -0,0 +1,15 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  var arr: [[i32;2];2] = ((1,2), (3,4));
+
+  var x : [[i32;];] = arr;
+  // CHECK:STDERR: RUNTIME ERROR: fail_to_index_deduced_nested_size_from_array.carbon:[[@LINE+1]]: index 2 out of range in (1, 2)
+  return x[0][2];
+}

explorer/testdata/array/fail_to_index_deduced_nested_size_from_tuple.carbon

@@ -0,0 +1,13 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  var x: [[i32;];] = ((1,2), (3,4));
+  // CHECK:STDERR: RUNTIME ERROR: fail_to_index_deduced_nested_size_from_tuple.carbon:[[@LINE+1]]: index 2 out of range in (1, 2)
+  return x[0][2];
+}

explorer/testdata/array/nested_and_external_array_size_deduction_from_tuple.carbon

@@ -0,0 +1,16 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  var x: [[i32;];] = ((1,2), (3,4));
+  x[0][1] = 1;
+  x[1][0] = 1;
+  return x[0][0] + x[0][1] + x[1][0] + x[1][1];
+}
+
+// CHECK:STDOUT: result: 7

explorer/testdata/array/nested_array_size_deduction_from_array.carbon

@@ -0,0 +1,18 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  var arr: [[i32;2];2] = ((1,2), (3,4));
+
+  var x : [[i32;];] = arr;
+  x[0][1] = 1;
+  x[1][0] = 1;
+  return x[0][0] + x[0][1] + x[1][0] + x[1][1];
+}
+
+// CHECK:STDOUT: result: 7

explorer/testdata/array/nested_array_size_deduction_from_empty_tuple.carbon

@@ -0,0 +1,14 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  var x: [[i32;];2] = ((), ());
+  return 42;
+}
+
+// CHECK:STDOUT: result: 42

explorer/testdata/array/nested_array_size_deduction_from_tuple.carbon

@@ -0,0 +1,16 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  var x: [[i32;];2] = ((1,2), (3,4));
+  x[0][1] = 1;
+  x[1][0] = 1;
+  return x[0][0] + x[0][1] + x[1][0] + x[1][1];
+}
+
+// CHECK:STDOUT: result: 7

explorer/testdata/array/nested_array_size_deduction_from_tuple_of_tuple_and_array.carbon

@@ -0,0 +1,17 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  var x: [i32; 2] = (1, 2);
+  var y: [[i32;];] = (x, (3,4));
+  y[0][1] = 1;
+  y[1][0] = 1;
+  return y[0][0] + y[0][1] + y[1][0] + y[1][1];
+}
+
+// CHECK:STDOUT: result: 7

explorer/testdata/array/three_dim_array_size_deduction_from_tuple.carbon

@@ -0,0 +1,16 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+package ExplorerTest api;
+
+fn Main() -> i32 {
+  let v: i32 = 8;
+  var x: [[[i32;];];] = (((1,2), (3,4)), ((5,6), (7,v)));
+  x[1][1][1] -= v;
+  return x[1][1][1];
+}
+
+// CHECK:STDOUT: result: 0