[clang-tools-extra] Add clang-tidy check to suggest replacement of conditional statement with std::min/std::max (PR #77816)

[via cfe-commits]

================
@@ -0,0 +1,88 @@
+//===--- ConditionaltostdminmaxCheck.cpp - clang-tidy ---------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ConditionaltostdminmaxCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+void ConditionaltostdminmaxCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      ifStmt(has(binaryOperator(
+                 anyOf(hasOperatorName("<"), hasOperatorName(">")),
+                 hasLHS(ignoringImpCasts(declRefExpr().bind("lhsVar1"))),
+                 hasRHS(ignoringImpCasts(declRefExpr().bind("rhsVar1"))))),
+             hasThen(stmt(binaryOperator(
+                 hasOperatorName("="),
+                 hasLHS(ignoringImpCasts(declRefExpr().bind("lhsVar2"))),
+                 hasRHS(ignoringImpCasts(declRefExpr().bind("rhsVar2")))))))
+          .bind("ifStmt"),
+      this);
+}
+
+void ConditionaltostdminmaxCheck::check(
+    const MatchFinder::MatchResult &Result) {
+  const DeclRefExpr *lhsVar1 = Result.Nodes.getNodeAs<DeclRefExpr>("lhsVar1");
----------------
EugeneZelenko wrote:

`const auto *` because type es spelled in same statement explicitly. Same in other similar places.

https://github.com/llvm/llvm-project/pull/77816