[gcc r13-4847] bootstrap/106482 - document minimal GCC version

[gcc r13-4847] bootstrap/106482 - document minimal GCC version

[Richard Biener]

https://gcc.gnu.org/g:b97c33fbd28e74a206c81c96a9b0b9fa3c8545d6

commit r13-4847-gb97c33fbd28e74a206c81c96a9b0b9fa3c8545d6
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Dec 22 15:51:46 2022 +0100

    bootstrap/106482 - document minimal GCC version
    
    There's no explicit mention of what GCC compiler supports C++11
    and the cross compiler build requirement mentions GCC 4.8 but not
    GCC 4.8.3 which is the earliest known version to not run into
    C++11 implementation bugs.  The following adds explicit wording.
    
            PR bootstrap/106482
            * doc/install.texi (ISO C++11 Compiler): Document GCC version
            known to work.

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

diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 5c0214b4e62..fc3a3cba552 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -227,7 +227,9 @@ described below.
 @heading Tools/packages necessary for building GCC
 @table @asis
 @item ISO C++11 compiler
-Necessary to bootstrap GCC.
+Necessary to bootstrap GCC.  GCC 4.8.3 or newer has sufficient
+support for used C++11 features, with earlier GCC versions you
+might run into implementation bugs.
 
 Versions of GCC prior to 11 also allow bootstrapping with an ISO C++98
 compiler, versions of GCC prior to 4.8 also allow bootstrapping with a
@@ -236,7 +238,7 @@ bootstrapping with a traditional (K&R) C compiler.
 
 To build all languages in a cross-compiler or other configuration where
 3-stage bootstrap is not performed, you need to start with an existing
-GCC binary (version 4.8 or later) because source code for language
+GCC binary (version 4.8.3 or later) because source code for language
 frontends other than C might use GCC extensions.
 
 @item C standard library and headers