stdlib: correct protocol registration on ELF

We were misinterpreting the protocol conformances as the protocol sections.  It
is interesting that this never was caught in any of the runs on the build bots
nor was it caught during the normal execution of code.

Author: compnerd

stdlib/public/runtime/ImageInspectionELF.cpp

@@ -111,7 +111,7 @@ void swift_addNewDSOImage(const void *addr) {
 
   record(sections);
 
-  const auto &protocols_section = sections->swift4_protocol_conformances;
+  const auto &protocols_section = sections->swift4_protocols;
   const void *protocols =
       reinterpret_cast<void *>(protocols_section.start);
   if (protocols_section.length)