Documentation: update for gcc 4.9 requirement

Update Documentation for the gcc v4.9 upgrade requirement.

Fixes: 5429ef62 ("compiler/gcc: Raise minimum GCC version for kernel builds to 4.8")
Fixes: 6ec4476a ("Raise gcc version requirement to 4.9")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/admin-guide/README.rst

@@ -258,7 +258,7 @@ Configuring the kernel
 Compiling the kernel
 --------------------
 
- - Make sure you have at least gcc 4.6 available.
+ - Make sure you have at least gcc 4.9 available.
    For more information, refer to :ref:`Documentation/process/changes.rst <changes>`.
 
    Please note that you can still run a.out user programs with this kernel.

Documentation/process/changes.rst

@@ -29,7 +29,7 @@ you probably needn't concern yourself with pcmciautils.
 ====================== ===============  ========================================
         Program        Minimal version       Command to check the version
 ====================== ===============  ========================================
-GNU C                  4.8              gcc --version
+GNU C                  4.9              gcc --version
 GNU make               3.81             make --version
 binutils               2.23             ld -v
 flex                   2.5.35           flex --version