[ORC] Skip ST_File symbols in MaterializationUnit interfaces / resolution.

ST_File symbols aren't relevant for linking purposes, but can end up shadowing
real symbols if they're not filtered.

No test case yet: The ideal testcase for this would be an ELF llvm-jitlink test,
but llvm-jitlink support for ELF is still under development. We should add a
testcase for this once support lands in tree.

llvm/lib/ExecutionEngine/Orc/Mangling.cpp

@@ -99,6 +99,13 @@ getObjectSymbolInfo(ExecutionSession &ES, MemoryBufferRef ObjBuffer) {
     if (!(Sym.getFlags() & object::BasicSymbolRef::SF_Global))
       continue;
 
+    // Skip symbols that have type SF_File.
+    if (auto SymType = Sym.getType()) {
+      if (*SymType == object::SymbolRef::ST_File)
+        continue;
+    } else
+      return SymType.takeError();
+
     auto Name = Sym.getName();
     if (!Name)
       return Name.takeError();

llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp

@@ -116,6 +116,18 @@ void RTDyldObjectLinkingLayer::emit(MaterializationResponsibility R,
   auto InternalSymbols = std::make_shared<std::set<StringRef>>();
   {
     for (auto &Sym : (*Obj)->symbols()) {
+
+      // Skip file symbols.
+      if (auto SymType = Sym.getType()) {
+        if (*SymType == object::SymbolRef::ST_File)
+          continue;
+      } else {
+        ES.reportError(SymType.takeError());
+        R.failMaterialization();
+        return;
+      }
+
+      // Don't include symbols that aren't global.
       if (!(Sym.getFlags() & object::BasicSymbolRef::SF_Global)) {
         if (auto SymName = Sym.getName())
           InternalSymbols->insert(*SymName);