[DebugInfoPDB] Add DIA implementation of findLineNumbersByRVA

This method is used to find line numbers for PDBSymbolData
that have an invalid virtual address.

llvm-svn: 328586
diff --git a/llvm/unittests/DebugInfo/PDB/PDBApiTest.cpp b/llvm/unittests/DebugInfo/PDB/PDBApiTest.cpp
index 314a013..0e439a6 100644
--- a/llvm/unittests/DebugInfo/PDB/PDBApiTest.cpp
+++ b/llvm/unittests/DebugInfo/PDB/PDBApiTest.cpp
@@ -97,6 +97,10 @@
     return nullptr;
   }
   std::unique_ptr<IPDBEnumLineNumbers>
+  findLineNumbersByRVA(uint32_t RVA, uint32_t Length) const override {
+    return nullptr;
+  }
+  std::unique_ptr<IPDBEnumLineNumbers>
   findLineNumbersBySectOffset(uint32_t Section, uint32_t Offset,
                               uint32_t Length) const override {
     return nullptr;