[clang] Docs: clarify standard library usage with C++ modules (PR #173636)

[via cfe-commits]

https://github.com/Viditgupta-official updated https://github.com/llvm/llvm-project/pull/173636

>From b121cbd43d9ec1d0109280c26b6683e3ec53500d Mon Sep 17 00:00:00 2001
From: Vidit <viditgupta.official at gmail.com>
Date: Fri, 26 Dec 2025 16:47:04 +0530
Subject: [PATCH] Docs: clarify standard library usage with C++ modules

This change clarifies clang's modules documentation to note that standard library facilities may be provided via C++ modules (e.g. `import std;`) rather than traditional header inclusion.

No functional changes intended.
---
 clang/docs/Modules.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/clang/docs/Modules.rst b/clang/docs/Modules.rst
index bfdb05ea459c3..58daa0187cd5c 100644
--- a/clang/docs/Modules.rst
+++ b/clang/docs/Modules.rst
@@ -73,6 +73,8 @@ Semantic import
 ---------------
 Modules improve access to the API of software libraries by replacing the textual preprocessor inclusion model with a more robust, more efficient semantic model. From the user's perspective, the code looks only slightly different, because one uses an ``import`` declaration rather than a ``#include`` preprocessor directive:
 
+In the case of the C++ standard library, importing a standard library module (for example via ``import std;``) provides access to standard library facilities without requiring the inclusion of individual standard library headers, and diagnostics may differ from the traditional header-based model.
+
 .. code-block:: c
 
   import std.io; // pseudo-code; see below for syntax discussion