Revert "Retry "Include debug info for nested structs and classes""

Reverting because it causes a test failure on build bots (Modules/ModuleDebugInfo.cpp).  Failure does not reproduce locally.

svn revision: rL274698

This reverts commit 3c5ed6599b086720aab5b8bd6941149d066806a6.

llvm-svn: 274706