Fix minor doc bugs, signalling typo, major version changes rare.

	gcc/
	* doc/cpp.texi (__GNUC__): Major version changes are no longer rare.
	* doc/invoke.texi (-mnan=2008): Change signalling to signaling.
	* doc/md.texi (fmin@var{m}3): Likewise.

From-SVN: r236340

gcc/ChangeLog

+2016-05-17  Jim Wilson  <jim.wilson@linaro.org>
+
+	* doc/cpp.texi (__GNUC__): Major version changes are no longer rare.
+	* doc/invoke.texi (-mnan=2008): Change signalling to signaling.
+	* doc/md.texi (fmin@var{m}3): Likewise.
+
 2016-05-17  Marc Glisse  <marc.glisse@inria.fr>
 
 	* match.pd (X & C): New transformation.

gcc/doc/cpp.texi

@@ -1984,7 +1984,7 @@ by GCC, or a non-GCC compiler that claims to accept the GNU C dialects,
 you can simply test @code{__GNUC__}.  If you need to write code
 which depends on a specific version, you must be more careful.  Each
 time the minor version is increased, the patch level is reset to zero;
-each time the major version is increased (which happens rarely), the
+each time the major version is increased, the
 minor version and patch level are reset.  If you wish to use the
 predefined macros directly in the conditional, you will need to write it
 like this:

gcc/doc/invoke.texi

@@ -18122,7 +18122,7 @@ IEEE 754 floating-point data.
 
 The @option{-mnan=legacy} option selects the legacy encoding.  In this
 case quiet NaNs (qNaNs) are denoted by the first bit of their trailing
-significand field being 0, whereas signalling NaNs (sNaNs) are denoted
+significand field being 0, whereas signaling NaNs (sNaNs) are denoted
 by the first bit of their trailing significand field being 1.
 
 The @option{-mnan=2008} option selects the IEEE 754-2008 encoding.  In

gcc/doc/md.texi

@@ -5018,7 +5018,7 @@ it is unspecified which of the two operands is returned as the result.
 IEEE-conformant minimum and maximum operations.  If one operand is a quiet
 @code{NaN}, then the other operand is returned.  If both operands are quiet
 @code{NaN}, then a quiet @code{NaN} is returned.  In the case when gcc supports
-signalling @code{NaN} (-fsignaling-nans) an invalid floating point exception is
+signaling @code{NaN} (-fsignaling-nans) an invalid floating point exception is
 raised and a quiet @code{NaN} is returned.
 
 All operands have mode @var{m}, which is a scalar or vector