Add operator< and operator== to linetable_entry

This adds a couple of comparison operators to linetable_entry, and
simplifies both the calls to sort and one other spot that checks for
equality.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

gdb/buildsym.c

@@ -891,25 +891,13 @@ buildsym_compunit::end_compunit_symtab_with_blockvector
     {
       if (!subfile->line_vector_entries.empty ())
 	{
-	  const auto lte_is_less_than
-	    = [] (const linetable_entry &ln1,
-		  const linetable_entry &ln2) -> bool
-	      {
-		if (ln1.pc == ln2.pc
-		    && ((ln1.line == 0) != (ln2.line == 0)))
-		  return ln1.line == 0;
-
-		return (ln1.pc < ln2.pc);
-	      };
-
 	  /* Like the pending blocks, the line table may be scrambled
 	     in reordered executables.  Sort it.  It is important to
 	     preserve the order of lines at the same address, as this
 	     maintains the inline function caller/callee
 	     relationships, this is why std::stable_sort is used.  */
 	  std::stable_sort (subfile->line_vector_entries.begin (),
-			    subfile->line_vector_entries.end (),
-			    lte_is_less_than);
+			    subfile->line_vector_entries.end ());
 	}
 
       /* Allocate a symbol table if necessary.  */

gdb/disasm.c

@@ -604,7 +604,7 @@ do_mixed_source_and_assembly_deprecated
 
   for (; i < nlines - 1 && le[i].pc < high; i++)
     {
-      if (le[i].line == le[i + 1].line && le[i].pc == le[i + 1].pc)
+      if (le[i] == le[i + 1])
 	continue;		/* Ignore duplicates.  */
 
       /* Skip any end-of-function markers.  */

gdb/symtab.h

@@ -1547,6 +1547,19 @@ struct rust_vtable_symbol : public symbol
 
 struct linetable_entry
 {
+  bool operator< (const linetable_entry &other) const
+  {
+    if (pc == other.pc
+	&& (line != 0) != (other.line != 0))
+      return line == 0;
+    return pc < other.pc;
+  }
+
+  /* Two entries are equal if they have the same line and PC.  The
+     other members are ignored.  */
+  bool operator== (const linetable_entry &other) const
+  { return line == other.line && pc == other.pc; }
+
   /* The line number for this entry.  */
   int line;
 

gdb/xcoffread.c

@@ -439,9 +439,7 @@ arrange_linetable (std::vector<linetable_entry> &old_linetable)
   if (fentries.empty ())
     return;
 
-  std::sort (fentries.begin (), fentries.end (),
-	     [] (const linetable_entry &lte1, const linetable_entry& lte2)
-	     { return lte1.pc < lte2.pc; });
+  std::sort (fentries.begin (), fentries.end ());
 
   /* Allocate a new line table.  */
   std::vector<linetable_entry> new_linetable;