[CK_BUILDER] Add inline string diff for tests (#3067)

Adds new testing functionality: an inline diff for string comparison.

Example usage:

EXPECT_THAT("Actual string", ck_tile::test::StringEqWithDiff("Expected string"));

Failure message:

Value of: "Actual string"
Expected: "Expected string"
Actual: "Actual string" (of type char [14]),
Diff: "[Expe|A]ct[ed|ual] string"

The inline-diff function uses the Wagner-Fischer algorithm to find the minimum edit distance and generate diff markers, which has O(N^2) complexity. It has optional color codes that are enabled with the matcher.

experimental/builder/test/test_inline_diff.cpp

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2025, Advanced Micro Devices, Inc. All rights reserved.
+
+#include <gtest/gtest.h>
+
+#include "testing_utils.hpp"
+
+namespace ck_tile::builder {
+namespace {
+
+TEST(InlineDiff, simpleColorDiff)
+{
+    std::string str1{"hello"};
+    std::string str2{"hello"};
+    std::string str3{"world"};
+
+    // some easy tests
+    // you can veryfy the ungodly strings are meaningful by running echo -e "<string>"
+    EXPECT_THAT(test::inlineDiff(str1, str2, true), "hello");
+    EXPECT_THAT(test::inlineDiff(str1, str3, true),
+                "[\x1B[36mwor\x1B[0m|\x1B[35mhel\x1B[0m]l[\x1B[36md\x1B[0m|\x1B[35mo\x1B[0m]");
+}
+
+TEST(InlineDiff, noColorDiff)
+{
+    std::string str1{"hello"};
+    std::string str2{"hello"};
+    std::string str3{"world"};
+
+    // some easy tests without color
+    EXPECT_THAT(test::inlineDiff(str1, str2, false), "hello");
+    EXPECT_THAT(test::inlineDiff(str1, str3, false), "[wor|hel]l[d|o]");
+}
+
+TEST(InlineDiff, complexColorDiff)
+{
+
+    // now something more interesting
+    std::string str4{"this part has changed, this part has been left out, this part, this part has "
+                     "an extra letter"};
+    std::string str5{
+        "this part has degeahc, this part has, this part added, this part has ana extra letter"};
+
+    EXPECT_THAT(
+        test::inlineDiff(str5, str4, true),
+        "this part has [\x1B[36mchanged\x1B[0m|\x1B[35mdegeahc\x1B[0m], this part has[\x1B[36m "
+        "been left out\x1B[0m|\x1B[35m\x1B[0m], this part[\x1B[36m\x1B[0m|\x1B[35m added\x1B[0m], "
+        "this part has an[\x1B[36m\x1B[0m|\x1B[35ma\x1B[0m] extra letter");
+};
+
+} // namespace
+} // namespace ck_tile::builder