Put modules for 32-bit iOS builds in lib/swift/iphone{os,simulator}/32.

This keeps us from having to deal with fat swiftmodules for now.
In the long run we're hoping to solve this problem with build configurations,
so that a single module file can support multiple architectures.
(See <rdar://problem/15056323>)

<rdar://problem/15204953>

Swift SVN r13135

lib/Serialization/SerializedModuleLoader.cpp

@@ -86,7 +86,7 @@ static llvm::error_code findModule(ASTContext &ctx, AccessPathElem moduleID,
   }
 
   // Search the runtime import path.
-  inputFilename = ctx.SearchPathOpts.RuntimeImportPath;
+  inputFilename = ctx.SearchPathOpts.RuntimeLibraryImportPath;
   llvm::sys::path::append(inputFilename, moduleFilename.str());
   err = llvm::MemoryBuffer::getFile(inputFilename.str(), bufferRef);
   if (!err) {