DWARF-5: Fix parsing DWARF-5 line number tables

Advance rngs_ptr when parsing DW_RLE_offset_pair, which was missing in

commit c3757b5
Author: Mark Wielaard <mark@klomp.org>
Date:   Tue Aug 25 15:33:00 2020 +0100

    Fix the linker's handling of DWARF-5 line number tables.

	PR binutils/27231
	* dwarf2.c (read_rnglists): Advance rngs_ptr after
	_bfd_safe_read_leb128 when parsing DW_RLE_offset_pair.

(cherry picked from commit 18454c1)

Author: hjl-tools

bfd/ChangeLog

@@ -1,3 +1,9 @@
+2021-01-23  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR binutils/27231
+	* dwarf2.c (read_rnglists): Advance rngs_ptr after
+	_bfd_safe_read_leb128 when parsing DW_RLE_offset_pair.
+
 2021-01-20  Alan Modra  <amodra@gmail.com>
 
 	* elf64-ppc.c (ppc64_elf_get_synthetic_symtab): Don't assume

bfd/dwarf2.c

@@ -3265,9 +3265,11 @@ read_rnglists (struct comp_unit *unit, struct arange *arange,
 	  low_pc = base_address;
 	  low_pc += _bfd_safe_read_leb128 (abfd, rngs_ptr, &bytes_read,
 					   FALSE, rngs_end);
+	  rngs_ptr += bytes_read;
 	  high_pc = base_address;
 	  high_pc += _bfd_safe_read_leb128 (abfd, rngs_ptr, &bytes_read,
 					    FALSE, rngs_end);
+	  rngs_ptr += bytes_read;
 	  break;
 
 	case DW_RLE_start_end: