Check for tombstone as very first entry in the line table.

This is a folow up to
https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2317730

and handles the additional case where there are no entries in the line
table at all.

Change-Id: I100c5d0891e7dc7088d58da11240d7df3a6c48d9
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2321300
Reviewed-by: Mark Mentovai <mark@chromium.org>

src/common/dwarf_cu_to_module.cc

@@ -1089,6 +1089,11 @@ void DwarfCUToModule::AssignLinesToFunctions() {
     return;
   }
 
+  // Some dwarf producers handle linker-removed functions by using -1 as a
+  // tombstone in the line table. So the end marker can be -1.
+  if (current == Module::kMaxAddress)
+    return;
+
   while (range || line) {
     // This loop has two invariants that hold at the top.
     //