[llvm] [doc] Add special case for unsupported test (PR #78858)

[via llvm-commits]

https://github.com/hiraditya updated https://github.com/llvm/llvm-project/pull/78858

>From a465071f96f03d9bf71f4fe5792c5432e8da1e83 Mon Sep 17 00:00:00 2001
From: AdityaK <1894981+hiraditya at users.noreply.github.com>
Date: Sat, 20 Jan 2024 12:17:40 -0800
Subject: [PATCH] Add special case for unsupported test

That helps disable the test for all the targets
---
 llvm/docs/TestingGuide.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/docs/TestingGuide.rst b/llvm/docs/TestingGuide.rst
index a692e301fa2c41f..e32e4d1e535abb7 100644
--- a/llvm/docs/TestingGuide.rst
+++ b/llvm/docs/TestingGuide.rst
@@ -568,7 +568,8 @@ list of boolean expressions. The values in each expression may be:
 | ``UNSUPPORTED`` disables the test if any expression is true.
 | ``XFAIL`` expects the test to fail if any expression is true.
 
-As a special case, ``XFAIL: *`` is expected to fail everywhere.
+Use, ``XFAIL: *`` if the test is expected to fail everywhere. Similarly, use
+``UNSUPPORTED: target={{.*}}`` to disable the test everywhere.
 
 .. code-block:: llvm