[C++ PATCH] 'std' identifier not needed

[Nathan Sidwell]

There's no need to retain "std" identifier as a global tree -- we can 
simply use {push,/pop}_ nested_namespace on the std_node we have there. 
Also simplify the in-std-namespace predicate by checking against std::node.

applying to trunk.

nathan
-- 
Nathan Sidwell
-------------- next part --------------
A non-text attachment was scrubbed...
Name: std.diff
Type: text/x-patch
Size: 5600 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20191024/8a90f272/attachment.bin>