docs: remove --disable-stage1-checking from requirements

As the minimal GCC version that can build the current master
is 4.8, it does not make sense mentioning something for older
versions.

gcc/ChangeLog:

	* doc/install.texi: Remove option for GCC < 4.8.

diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 96b4dfc..f4e7dc4 100644 (file)
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -239,11 +239,6 @@ To build all languages in a cross-compiler or other configuration where
 GCC binary (version 4.8 or later) because source code for language
 frontends other than C might use GCC extensions.
 
-Note that to bootstrap GCC with versions of GCC earlier than 4.8, you
-may need to use @option{--disable-stage1-checking}, though
-bootstrapping the compiler with such earlier compilers is strongly
-discouraged.
-
 @item C standard library and headers
 
 In order to build GCC, the C standard library and headers must be present