ibstdc++: Add some further attributes to ::operator new in <new>

ibstdc++: Add some further attributes to ::operator new in <new>

I've noticed alloc_align attribute is missing on the non-vector
::operator new with std::align_val_t and const std::nothrow_t&
arguments, this patch adds it.  The last hunk is just
an attempt to make the line shorter.
The first hunk originally added also __alloc_size__ (1) attribute,
but seems that regresses
FAIL: g++.dg/tm/pr46270.C  -std=gnu++98 (test for excess errors)
with
Excess errors:
.../libstdc++-v3/libsupc++/new:137:26: warning: new declaration 'void* operator new(std::size_t)' ambiguates built-in declaration 'void* operator new(long unsigned int)
+transaction_safe' [-Wbuiltin-declaration-mismatch]
.../libstdc++-v3/libsupc++/new:140:26: warning: new declaration 'void* operator new [](std::size_t)' ambiguates built-in declaration 'void* operator new [](long unsigned int)
+transaction_safe' [-Wbuiltin-declaration-mismatch]
I must say I have no clue why that happens only in C++98 (C++11 and
above are quiet) and why only with -fgnu-tm, tried to debug that but
am lost.  It is some conflict with the predeclared ::operator new, but
those clearly do have the externally_visible attribute, and alloc_size (1)
attributes:
     extvisattr = build_tree_list (get_identifier ("externally_visible"),
                                   NULL_TREE);
     newattrs = tree_cons (get_identifier ("alloc_size"),
                           build_tree_list (NULL_TREE, integer_one_node),
                           extvisattr);
     newtype = cp_build_type_attribute_variant (ptr_ftype_sizetype, newattrs);
     newtype = build_exception_variant (newtype, new_eh_spec);
...
    tree opnew = push_cp_library_fn (NEW_EXPR, newtype, 0);
    DECL_IS_MALLOC (opnew) = 1;
    DECL_SET_IS_OPERATOR_NEW (opnew, true);
    DECL_IS_REPLACEABLE_OPERATOR (opnew) = 1;
and at C++98 I think libstdc++ doesn't add transaction_safe attribute:
 // Conditionally enable annotations for the Transactional Memory TS on C++11.
 // Most of the following conditions are due to limitations in the current
 // implementation.
 #if __cplusplus >= 201103L && _GLIBCXX_USE_CXX11_ABI                    \
   && _GLIBCXX_USE_DUAL_ABI && __cpp_transactional_memory >= 201500L     \
   &&  !_GLIBCXX_FULLY_DYNAMIC_STRING && _GLIBCXX_USE_WEAK_REF           \
   && _GLIBCXX_USE_ALLOCATOR_NEW
 #define _GLIBCXX_TXN_SAFE transaction_safe
 #define _GLIBCXX_TXN_SAFE_DYN transaction_safe_dynamic
 #else
 #define _GLIBCXX_TXN_SAFE
 #define _GLIBCXX_TXN_SAFE_DYN
 #endif
push_cp_library_fn adds transaction_safe attribute whenever -fgnu-tm
is used, regardless of the other conditionals:
   if (flag_tm)
     apply_tm_attr (fn, get_identifier ("transaction_safe"));

Anyway, omitting alloc_size (1) fixes that test and given that the
predeclared operator new already has alloc_size (1) attribute, I think it
can be safely left out.

2024-11-08  Jakub Jelinek  <jakub@redhat.com>

	* libsupc++/new (::operator new, ::operator new[]): Add malloc
	attribute where missing.  Add alloc_align attribute when
	std::align_val_t is present and where it was missing.  Formatting fix.