Add namespace_name field to zend_op_array for visibility checks

To support namespace-scoped visibility, we need to track which namespace
each function/file belongs to at runtime. This commit adds a namespace_name
field to zend_op_array that is set during compilation from CG(file_context).current_namespace.

This allows determining the caller's namespace context even for top-level code.

* Memory cost: 8 bytes per op_array on 64-bit systems

Author: withinboredom

Zend/zend_compile.c

@@ -8563,6 +8563,10 @@ static zend_op_array *zend_compile_func_decl_ex(
 		op_array->fn_flags |= ZEND_ACC_PRELOADED;
 	}
 
+	if (CG(file_context).current_namespace) {
+		op_array->namespace_name = zend_string_copy(CG(file_context).current_namespace);
+	}
+
 	op_array->fn_flags |= (orig_op_array->fn_flags & ZEND_ACC_STRICT_TYPES);
 	op_array->fn_flags |= decl->flags;
 	op_array->line_start = decl->start_lineno;

Zend/zend_compile.h

@@ -560,6 +560,7 @@ struct _zend_op_array {
 	zend_string *filename;
 	uint32_t line_start;
 	uint32_t line_end;
+	zend_string *namespace_name;
 
 	uint32_t last_literal;
 	uint32_t num_dynamic_func_defs;

Zend/zend_language_scanner.l

@@ -609,6 +609,10 @@ static zend_op_array *zend_compile(int type)
 		init_op_array(op_array, type, INITIAL_OP_ARRAY_SIZE);
 		CG(active_op_array) = op_array;
 
+		if (CG(file_context).current_namespace) {
+			op_array->namespace_name = zend_string_copy(CG(file_context).current_namespace);
+		}
+
 		/* Use heap to not waste arena memory */
 		op_array->fn_flags |= ZEND_ACC_HEAP_RT_CACHE;
 

Zend/zend_opcode.c

@@ -66,6 +66,7 @@ void init_op_array(zend_op_array *op_array, uint8_t type, int initial_ops_size)
 	op_array->filename = zend_string_copy(zend_get_compiled_filename());
 	op_array->doc_comment = NULL;
 	op_array->attributes = NULL;
+	op_array->namespace_name = NULL;
 
 	op_array->arg_info = NULL;
 	op_array->num_args = 0;
@@ -611,6 +612,9 @@ ZEND_API void destroy_op_array(zend_op_array *op_array)
 	if (op_array->doc_comment) {
 		zend_string_release_ex(op_array->doc_comment, 0);
 	}
+	if (op_array->namespace_name) {
+		zend_string_release_ex(op_array->namespace_name, 0);
+	}
 	if (op_array->attributes) {
 		zend_hash_release(op_array->attributes);
 	}