[flang-commits] [flang] [flang][NFC] Restore documentation (PR #78211)

[Peter Klausler via flang-commits]

https://github.com/klausler created https://github.com/llvm/llvm-project/pull/78211

Add a paragraph to Extensions.md that fell out of a recent patch.

>From 2eede1d40ca85b2b131d6e07368ca0414be3eb91 Mon Sep 17 00:00:00 2001
From: Peter Klausler <pklausler at nvidia.com>
Date: Thu, 4 Jan 2024 14:39:46 -0800
Subject: [PATCH] [flang][NFC] Restore documentation

Add a paragraph to Extensions.md that fell out of a recent
patch.
---
 flang/docs/Extensions.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/flang/docs/Extensions.md b/flang/docs/Extensions.md
index 259dc652b4e2be..28f672ac28596d 100644
--- a/flang/docs/Extensions.md
+++ b/flang/docs/Extensions.md
@@ -107,6 +107,12 @@ end
   These definitions yield fairly poor results due to floating-point
   cancellation, and every Fortran compiler (including this one)
   uses better algorithms.
+* When an index variable of a `FORALL` or `DO CONCURRENT` is present
+  in the enclosing scope, and the construct does not have an explicit
+  type specification for its index variables, some weird restrictions
+  in F'2023 subclause 19.4 paragraphs 6 & 8 should apply.  Since this
+  compiler properly scopes these names, violations of these restrictions
+  elicit only portability warnings by default.
 
 ## Extensions, deletions, and legacy features supported by default