C, fix object types for xrefs

Add 'identifer' to all and 'type' to types.

Fixes sphinx-doc/sphinx#8341

tests/roots/test-domain-c-intersphinx/conf.py

@@ -0,0 +1,4 @@
+exclude_patterns = ['_build']
+extensions = [
+	'sphinx.ext.intersphinx',
+]

tests/roots/test-domain-c-intersphinx/index.rst

@@ -0,0 +1,62 @@
+.. c:member:: void __member = _member
+
+	- :any:`_member`
+	- :c:member:`_member`
+	- :c:var:`_member`
+	- :c:data:`_member`
+
+.. c:member:: void __var = _var
+
+	- :any:`_var`
+	- :c:member:`_var`
+	- :c:var:`_var`
+	- :c:data:`_var`
+
+.. c:member:: void __function = _function
+
+	- :any:`_function`
+	- :c:func:`_function`
+	- :c:type:`_function`
+
+.. c:member:: void __macro = _macro
+
+	- :any:`_macro`
+	- :c:macro:`_macro`
+
+.. c:type:: _struct __struct
+            struct _struct __structTagged
+
+	- :any:`_struct`
+	- :c:struct:`_struct`
+	- :c:type:`_struct`
+
+.. c:type:: _union __union
+            union _union __unionTagged
+
+	- :any:`_union`
+	- :c:union:`_union`
+	- :c:type:`_union`
+
+.. c:type:: _enum __enum
+            enum _enum __enumTagged
+
+	- :any:`_enum`
+	- :c:enum:`_enum`
+	- :c:type:`_enum`
+
+.. c:member:: void __enumerator = _enumerator
+
+	- :any:`_enumerator`
+	- :c:enumerator:`_enumerator`
+
+.. c:type:: _type __type
+
+	- :any:`_type`
+	- :c:type:`_type`
+
+.. c:member:: void __functionParam = _functionParam.param
+
+	- :any:`_functionParam.param`
+	- :c:member:`_functionParam.param`
+	- :c:var:`_functionParam.param`
+	- :c:data:`_functionParam.param`