[gcc r14-9994] Document that vector_size works with typedefs [PR92880]

[Andrew Pinski <pinskia@gcc.gnu.org>]

https://gcc.gnu.org/g:8eddd87da2dd01c841f9742f973f65ebe0a88e71

commit r14-9994-g8eddd87da2dd01c841f9742f973f65ebe0a88e71
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date:   Mon Apr 15 17:13:36 2024 -0700

    Document that vector_size works with typedefs [PR92880]
    
    This just adds a clause to make it more obvious that the vector_size
    attribute extension works with typedefs.
    Note this whole section needs a rewrite to be a similar format as other
    extensions. But that is for another day.
    
    gcc/ChangeLog:
    
            PR c/92880
            * doc/extend.texi (Using Vector Instructions): Add that
            the base_types could be a typedef of them.
    
    Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

Diff:
---
 gcc/doc/extend.texi | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 7b54a241a7b..e290265d68d 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -12901,12 +12901,13 @@ typedef int v4si __attribute__ ((vector_size (16)));
 @end smallexample
 
 @noindent
-The @code{int} type specifies the @dfn{base type}, while the attribute specifies
-the vector size for the variable, measured in bytes.  For example, the
-declaration above causes the compiler to set the mode for the @code{v4si}
-type to be 16 bytes wide and divided into @code{int} sized units.  For
-a 32-bit @code{int} this means a vector of 4 units of 4 bytes, and the
-corresponding mode of @code{foo} is @acronym{V4SI}.
+The @code{int} type specifies the @dfn{base type} (which can be a
+@code{typedef}), while the attribute specifies the vector size for the
+variable, measured in bytes. For example, the declaration above causes
+the compiler to set the mode for the @code{v4si} type to be 16 bytes wide
+and divided into @code{int} sized units.  For a 32-bit @code{int} this
+means a vector of 4 units of 4 bytes, and the corresponding mode of
+@code{foo} is @acronym{V4SI}.
 
 The @code{vector_size} attribute is only applicable to integral and
 floating scalars, although arrays, pointers, and function return values