[binutils-gdb/gdb-7.10-branch] Demangler: Fix constructor names with ABI tags

[sergiodj+buildbot at redhat dot com]

*** TEST RESULTS FOR COMMIT 99eda040d8214d2d691ba804d6354c99b6df5269 ***

Author: Ian Lance Taylor <iant@google.com>
Branch: gdb-7.10-branch
Commit: 99eda040d8214d2d691ba804d6354c99b6df5269

Demangler: Fix constructor names with ABI tags

The symbol _ZNSt8ios_base7failureB5cxx11C1EPKcRKSt10error_code, which
appears in libstdc++, was being demangled as

std::ios_base::failure[abi:cxx11]::cxx11(char const*, std::error_code const&)

That is clearly incorrect: std::ios_base::failure does not have a
method cxx11, and anyhow if you look closely at the mangled name you
will see that it is supposed to be a constructor.  This patch fixes
the demangler to generate the correct demangling, namely

std::ios_base::failure[abi:cxx11]::failure(char const*, std::error_code const&)

Bootstrapped and ran libiberty and libstdc++-v3 tests on
x86_64-unknown-linux-gnu.

2015-08-15  Ian Lance Taylor  <iant@google.com>

	* cp-demangle.c (d_abi_tags): Preserve di->last_name across any
	ABI tags.