[gcc r13-6612] Docs: Clean up description of asan-kernel-mem-intrinsic-prefix.

[Sandra Loosemore <sandra@gcc.gnu.org>]

https://gcc.gnu.org/g:f56ed5b3bcb9d94c0169d56b8bf652c7b5aa9fd3

commit r13-6612-gf56ed5b3bcb9d94c0169d56b8bf652c7b5aa9fd3
Author: Sandra Loosemore <sandra@codesourcery.com>
Date:   Sun Mar 12 03:41:11 2023 +0000

    Docs: Clean up description of asan-kernel-mem-intrinsic-prefix.
    
    gcc/ChangeLog:
            * doc/invoke.texi (Optimize Options):  Add markup to
            description of asan-kernel-mem-intrinsic-prefix, and clarify
            wording slightly.

Diff:
---
 gcc/doc/invoke.texi | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 3a6a97862b0..8d71d3d6ea5 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -15871,8 +15871,10 @@ E.g. to disable inline code use
 @option{--param asan-instrumentation-with-call-threshold=0}.
 
 @item asan-kernel-mem-intrinsic-prefix
-Prefix calls to memcpy, memset and memmove with __asan_ or __hwasan_
-for -fsanitize=kernel-address or -fsanitize=kernel-hwaddress.
+If nonzero, prefix calls to @code{memcpy}, @code{memset} and @code{memmove}
+with @samp{__asan_} or @samp{__hwasan_}
+for @option{-fsanitize=kernel-address} or @samp{-fsanitize=kernel-hwaddress},
+respectively.
 
 @item hwasan-instrument-stack
 Enable hwasan instrumentation of statically sized stack-allocated variables.