[llvm] Edit Semantics Description of `@llvm.is.constant.*` (PR #77519)

[via llvm-commits]

https://github.com/NCGThompson created https://github.com/llvm/llvm-project/pull/77519

Fixes #77517 

I edited it from browser and didn't run any checks due to the triviality of the change.

>From 57987b237bc85ffad0f57173a6f6f5627c26ca67 Mon Sep 17 00:00:00 2001
From: Nic <NCGThompson at gmail.com>
Date: Tue, 9 Jan 2024 15:39:12 -0500
Subject: [PATCH] Edit LangRef for @llvm.is.constant.*

Removed a sentence from the functions description because it was neither true or helpful.
---
 llvm/docs/LangRef.rst | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index c90b6becae5254..a16899205b22e5 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -27220,9 +27220,6 @@ obviously not constant. However, a call like
 function is inlined, if the value passed to the function parameter was
 a constant.
 
-On the other hand, if constant folding is not run, it will never
-evaluate to true, even in simple cases.
-
 .. _int_ptrmask:
 
 '``llvm.ptrmask``' Intrinsic