[PATCH] [core] add support to resolve section groups.

[Rui Ueyama]

================
Comment at: lib/Core/Resolver.cpp:219
@@ +218,3 @@
+    // for the first time
+    if (isFirstTime) {
+      for (const Reference *r : atom) {
----------------
Is this the correct semantics? If it's not a COMDAT group, we have to report an error for duplicate section group, no?


http://llvm-reviews.chandlerc.com/D3182