This overrides Enumerable#to_h, but doesn't handle a block, breaking
backwards compatibility.
Set#to_h was added in the marshalling support commit, but isn't
necessary for that, as the underlying function is called. Remove
the method definition to restore backwards compatibility.
In Ruby < 3.0, the superclass of StringIO was actually already `Data`,
but it doesn't have the expected shape. So, on these earlier versions it errors:
> NoMethodError: undefined method `members' for #<StringIO:0x00005641dd5f2880>
> vendor/bundle/ruby/2.6.0/gems/psych-5.2.5/lib/psych/visitors/yaml_tree.rb:170:in `visit_Data'
This test doesn't fail on 2.7, presumably because it can pull in a newer `stringio` version.
https://github.com/ruby/psych/commit/0f40f56268
Fix Visual C warnings:
```
iseq.c(3793): warning C4312: 'type cast': conversion from 'int' to 'void *' of greater size
iseq.c(3794): warning C4312: 'type cast': conversion from 'int' to 'void *' of greater size
```
When the test is repeated 20 or more times in the same process
it's not that unlikely for `rand(100_000)` to return the same thing
twice, causing `TestObjectIdTooComplexClass` to fail.
```
1) Failure:
TestObjectIdTooComplexClass#test_dup_with_id_and_ivar [/tmp/ruby/src/trunk-repeat20-asserts/test/ruby/test_object_id.rb:172]:
Expected #<struct RubyVM::Shape
id=6783,
parent_id=6774,
edge_name=:@___26417,
next_field_index=2,
heap_index=0,
type=1,
capacity=7> to be too_complex?.
```
../namespace.c: In function ‘current_namespace’:
../namespace.c:221:48: warning: ‘proc_ns’ may be used uninitialized [-Wmaybe-uninitialized]
221 | if (permit_calling_builtin || (proc_ns && NAMESPACE_USER_P(proc_ns)))
| ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../namespace.c:204:31: note: ‘proc_ns’ was declared here
204 | const rb_namespace_t *proc_ns;
| ^~~~~~~
In function ‘copy_ext_file’,
inlined from ‘rb_namespace_local_extension’ at ../namespace.c:855:18:
../namespace.c:768:21: warning: ‘written’ may be used uninitialized [-Wmaybe-uninitialized]
768 | wrote = fwrite(buffer+written, 1, read-written, dst);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../namespace.c: In function ‘rb_namespace_local_extension’:
../namespace.c:748:25: note: ‘written’ was declared here
748 | size_t read, wrote, written;
| ^~~~~~~
In function ‘copy_ext_file’,
inlined from ‘rb_namespace_local_extension’ at ../namespace.c:855:18:
../namespace.c:768:21: warning: ‘read’ may be used uninitialized [-Wmaybe-uninitialized]
768 | wrote = fwrite(buffer+written, 1, read-written, dst);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../namespace.c: In function ‘rb_namespace_local_extension’:
../namespace.c:748:12: note: ‘read’ was declared here
748 | size_t read, wrote, written;
| ^~~~
The intial complex shape implementation never allowed objects
other than T_OBJECT to become too complex, unless we run out of
shapes.
I don't see any reason to prevent that.
Ref: https://github.com/ruby/ruby/pull/6931
```
/opt/rubies/head-namespaces/bin/ruby(sigsegv+0x84) [0x104e897e8]
/usr/lib/system/libsystem_platform.dylib(_sigtramp+0x38) [0x18de56de4]
/opt/rubies/head-namespaces/bin/ruby(object_id+0x80) [0x104d7d420]
/opt/rubies/head-namespaces/bin/ruby(object_id+0x80) [0x104d7d420]
/opt/rubies/head-namespaces/bin/ruby(rb_initialize_main_namespace+0xe4) [0x104ddaa20]
/opt/rubies/head-namespaces/bin/ruby(ruby_opt_init+0x120) [0x104e7f524]
/opt/rubies/head-namespaces/bin/ruby(ruby_process_options+0x1370) [0x104e7e31c]
/opt/rubies/head-namespaces/bin/ruby(ruby_options+0xb0) [0x104d69844]
/opt/rubies/head-namespaces/bin/ruby(main+0x64) [0x104ca8d54]
```
I'm not too sure why `rb_obj_id` crashes, but I suspect it's called too
early. Either way I don't think generating an object_id for namespaces
is a good idea. If all we need is a unique number we can do that
for much cheaper.
The macro RCLASS_EXT() accesses the prime classext directly, but it can be
valid only in a limited situation when namespace is enabled.
So, to prevent using RCLASS_EXT() in the wrong way, rename the macro and
let the developer check it is ok to access the prime classext or not.
To make RClass size smaller, move flags of prime classext readable/writable to:
readable - use ns_classext_tbl is NULL or not (if NULL, it's readable)
writable - use FL_USER2 of RBasic flags
`rb_define_private_method` performs strict type checking on the function
pointer. As a result, we cannot pass the function a generic signature.
```
/github/workspace/src/namespace.c:1097:72: note: expected 'VALUE (*)(void)' {aka 'long unsigned int (*)(void)'} but argument is of type 'VALUE (*)(int, VALUE *, VALUE)' {aka 'long unsigned int (*)(int, long unsigned int *, long unsigned int)'}
1097 | namespace_define_loader_method(VALUE module, const char *name, VALUE (*func)(ANYARGS), int argc)
| ~~~~~~~~^~~~~~~~~~~~~~
```
This commit defines the method directly to avoid the mismatch error.
