LDMD: Avoid unitialized data.

Found using Valgrind.

driver/ldmd.cpp

@@ -483,11 +483,13 @@ struct Params
     pic(false),
     emitMap(false),
     multiObj(false),
+    debugInfo(Debug::none),
     alwaysStackFrame(false),
     profile(false),
     verbose(false),
     vdmd(false),
     logTlsUse(false),
+    warnings(Warnings::none),
     optimize(false),
     noObj(false),
     objDir(0),

gen/llvmhelpers.cpp

@@ -1022,6 +1022,7 @@ void DtoVarDeclaration(VarDeclaration* vd)
     assert(!vd->aliassym && "Aliases are handled in DtoDeclarationExp.");
 
     Logger::println("vdtype = %s", vd->type->toChars());
+    LOG_SCOPE
 
     if (vd->nestedrefs.dim)
     {