llvm-mc: .lsym is more unsupported than unimplemented, pending a use case appearing.

Also, all one of the file level flags are implemented.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80352 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index e972225..4ac0917 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -170,13 +170,12 @@
 
 void MCMachOStreamer::EmitAssemblerFlag(AssemblerFlag Flag) {
   switch (Flag) {
-  default:
-    llvm_unreachable("FIXME: Not yet implemented!");
-
   case SubsectionsViaSymbols:
     Assembler.setSubsectionsViaSymbols(true);
-    break;
+    return;
   }
+
+  assert(0 && "invalid assembler flag!");
 }
 
 void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol,
@@ -268,7 +267,8 @@
 }
 
 void MCMachOStreamer::EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {
-  llvm_unreachable("FIXME: Not yet implemented!");
+  // FIXME: Implement?
+  llvm_report_error("unsupported '.lsym' directive");
 }
 
 void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,