Backport fix for spurious anonymous ns warnings PR29365 to 4.2?

7 msg	Updating an operand in RTL for a builtin function
4 msg	Expression with 2 operations
6 msg	GCC 4.1: Problem with old-loop and REG_EQUAL notes
12 msg	bugzilla broken?
1 msg	Always generate warning/error for assignment as...
17 msg	GCC 4.2.0 RC3 Available
1 msg	Successful build of 4.2.0 RC2 for target=avr ho...
4 msg	__ffssi2 not exported in libgcc_s.so
4 msg	Bootstrap comparison differnce(s) on cygwin wit...
1 msg	Strange timings on nocona/prescott with indirec...
2 msg	where tokens are generated
2 msg	Bootstrap failure on i386-unknown-freebsd6.2: c...
1 msg	How to generate x86 seto/sets instructions?

Backport fix for spurious anonymous ns warnings...
\ Aaron W. LaFramboise (1 May 2007)
. \ Ian Lance Taylor (1 May 2007)
. . \ Andrew Pinski (1 May 2007)
. . . \ Seongbae Park (1 May 2007)
. . . . \ Mark Mitchell (2 May 2007)
. . . . . \ Seongbae Park (2 May 2007)

2 msg	GCC 4.2 RC2 Available
1 msg	some 4.2.0 RC2 test results
3 msg	Cygwin build documentation error.
15 msg	Information about LTO
10 msg	Re: 2nd quarter of 2007 and no GPL code of Java...
1 msg	gcc-4.1-20070430 is now available

Subject:	Backport fix for spurious anonymous ns warnings PR29365 to 4.2?
Group:	Gcc
From:	Aaron W. LaFramboise
Date:	1 May 2007

I discovered PR29365 today while testing 4.2.0 RC2 on a client's
codebase. This causes some of my code, based on the popular pimpl
idiom, to generate warnings, even with no warning flags specified. If
there's a way to turn it off without patching the source, I can't find it.

Given the pervasiveness of the pimpl idiom in C++, and the increasing
use of anonymous namespaces in modern code, it is possible that this
will be a serious problem for some C++ developers, that may hinder the
adoption of 4.2. It's not hard to imagine that this could come up in a
lot of other weird places that uses anonymous namespaces, too.

Does this qualify as a regression? Does anyone else think this is a
serious problem?