fix PR c++/16117

fix PR c++/16117

This patch fixes PR c++/16117.

gdb has an extension so that users can use expressions like FILE::NAME
to choose a variable of the given name from the given file.  The bug
is that this extension takes precedence over ordinary C++ expressions
of the same form.  You might think this is merely hypothetical, but
now that C++ headers commonly do not use an extension, it is more
common.

This patch fixes the bug by making two related changes.  First, it
changes gdb to prefer the ordinary C++ meaning of a symbol over the
extended meaning.  Second, it arranges for single-quoting of the
symbol to indicate a preference for the extension.

Built and regtested on x86-64 Fedora 18.
New test case included.

2013-11-15  Tom Tromey  <tromey@redhat.com>

	PR c++/16117:
	* c-exp.y (lex_one_token): Add "is_quoted_name" argument.
	(classify_name): Likewise.  Prefer a field of "this" over a
	filename.
	(classify_inner_name, yylex): Update.

2013-11-15  Tom Tromey  <tromey@redhat.com>

	* gdb.texinfo (Variables): Note gdb rules for ambiguous cases.
	Add example.

2013-11-15  Tom Tromey  <tromey@redhat.com>

	* gdb.cp/includefile: New file.
	* gdb.cp/filename.exp: New file.
	* gdb.cp/filename.cc: New file.