Fixed incorrect comment in SwiftReflectionTest

This code directly references several sections in the __TEXT segment but the comment refers to __DATA.

Author: daeken

stdlib/private/SwiftReflectionTest/SwiftReflectionTest.swift

@@ -107,7 +107,7 @@ internal func getSectionInfo(_ name: String,
 
 /// Get the Swift Reflection section locations for a loaded image.
 ///
-/// An image of interest must have the following sections in the __DATA
+/// An image of interest must have the following sections in the __TEXT
 /// segment:
 /// - __swift5_fieldmd
 /// - __swift5_assocty