Support reading section ".gnu_debugaltlink"

Differential revision: https://reviews.llvm.org/D40468

llvm-svn: 331148
diff --git a/lldb/source/Symbol/ObjectFile.cpp b/lldb/source/Symbol/ObjectFile.cpp
index a0cd94a..9210b75 100644
--- a/lldb/source/Symbol/ObjectFile.cpp
+++ b/lldb/source/Symbol/ObjectFile.cpp
@@ -363,6 +363,7 @@
           case eSectionTypeDWARFAppleTypes:
           case eSectionTypeDWARFAppleNamespaces:
           case eSectionTypeDWARFAppleObjC:
+          case eSectionTypeDWARFGNUDebugAltLink:
             return eAddressClassDebug;
           case eSectionTypeEHFrame:
           case eSectionTypeARMexidx: