[Ada] Adjust description of Pure_Function pragma

[Pierre-Marie de Rodat via Gcc-patches]

The current wording can be read as implying that the result of a call
to a pure function does not depend on the context, which is incorrect.
The pragma only guarantees the absence of side effects of such a call.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

        * doc/gnat_rm/implementation_defined_pragmas.rst (Pure_Function):
        Fix ambiguous wording about context dependence.
        * gnat_rm.texi: Regenerate.
diff --git a/gcc/ada/doc/gnat_rm/implementation_defined_pragmas.rst b/gcc/ada/doc/gnat_rm/implementation_defined_pragmas.rst
--- a/gcc/ada/doc/gnat_rm/implementation_defined_pragmas.rst
+++ b/gcc/ada/doc/gnat_rm/implementation_defined_pragmas.rst
@@ -5504,9 +5504,9 @@ overloaded declaration exists, in which case the pragma applies
 to all entities).  It specifies that the function ``Entity`` is
 to be considered pure for the purposes of code generation.  This means
 that the compiler can assume that there are no side effects, and
-in particular that two calls with identical arguments produce the
-same result.  It also means that the function can be used in an
-address clause.
+in particular that two identical calls produce the same result in
+the same context. It also means that the function can be used in
+an address clause.
 
 Note that, quite deliberately, there are no static checks to try
 to ensure that this promise is met, so ``Pure_Function`` can be used


diff --git a/gcc/ada/gnat_rm.texi b/gcc/ada/gnat_rm.texi
--- a/gcc/ada/gnat_rm.texi
+++ b/gcc/ada/gnat_rm.texi
@@ -21,7 +21,7 @@
 
 @copying
 @quotation
-GNAT Reference Manual , May 24, 2022
+GNAT Reference Manual , Jun 24, 2022
 
 AdaCore
 
@@ -7088,9 +7088,9 @@ overloaded declaration exists, in which case the pragma applies
 to all entities).  It specifies that the function @code{Entity} is
 to be considered pure for the purposes of code generation.  This means
 that the compiler can assume that there are no side effects, and
-in particular that two calls with identical arguments produce the
-same result.  It also means that the function can be used in an
-address clause.
+in particular that two identical calls produce the same result in
+the same context. It also means that the function can be used in
+an address clause.
 
 Note that, quite deliberately, there are no static checks to try
 to ensure that this promise is met, so @code{Pure_Function} can be used