[MC/Dwarf] Allow to specify custom parameters for linetable emission.

NFC patch for current users, but llvm-dsymutil will use the new
functionality to adapt to the input linetable.

Based on a patch by Adrian Prantl.

llvm-svn: 244318
diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index ffb14794..38e1261 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -1026,7 +1026,8 @@
   SmallString<8> &Data = DF.getContents();
   Data.clear();
   raw_svector_ostream OSE(Data);
-  MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OSE);
+  MCDwarfLineAddr::Encode(Context, getDWARFLinetableParams(), LineDelta,
+                          AddrDelta, OSE);
   OSE.flush();
   return OldSize != Data.size();
 }