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

[Félix-Antoine Constantin via cfe-commits]

================
@@ -0,0 +1,195 @@
+//===--- UseStdMinMaxCheck.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 "UseStdMinMaxCheck.h"
+#include "../utils/ASTUtils.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Preprocessor.h"
+#include <iostream>
+using namespace std;
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+class ExprVisitor : public clang::RecursiveASTVisitor<ExprVisitor> {
+public:
+  explicit ExprVisitor(clang::ASTContext *Context) : Context(Context) {}
+  bool visitStmt(const clang::Stmt *S, bool &found,
+                 clang::QualType &GlobalImplicitCastType) {
+
+    if (isa<clang::ImplicitCastExpr>(S) && !found) {
----------------
felix642 wrote:

You might want to (ignore/filter) some implicit cast types otherwise code like this one might give you some unexpected results:

```
#include <vector>

class Foo
{};

int bar()
{
    std::vector<std::vector<Foo>> a;
    unsigned int b = a[0].size();
    if(a[0].size() > b)
        b = a[0].size();
}
```
https://godbolt.org/z/M67o5hxrG

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