[lldb] Add support for recognizing swift ast sections in object files

In Apple's downstream fork, there is support for understanding the swift
AST sections in various binaries. Even though the lldb on llvm.org does
not have support for debugging swift, I think it makes sense to move
support for recognizing swift ast sections upstream.

Differential Revision: https://reviews.llvm.org/D159142

lldb/source/Symbol/ObjectFile.cpp

@@ -357,6 +357,7 @@ AddressClass ObjectFile::GetAddressClass(addr_t file_addr) {
           case eSectionTypeDWARFAppleObjC:
           case eSectionTypeDWARFGNUDebugAltLink:
           case eSectionTypeCTF:
+          case eSectionTypeSwiftModules:
             return AddressClass::eDebug;
           case eSectionTypeEHFrame:
           case eSectionTypeARMexidx: