PowerPC64 synthetic symbols

If an assembler trims off unused section symbols there may be no
section symbols.  This means that testing for the .opd section symbol
needs to test both the section name and symbol flags.

	* elf64-ppc.c (ppc64_elf_get_synthetic_symtab): Don't assume
	section symbols are present.

(cherry picked from commit 8bd10d6)

Author: amodra

bfd/ChangeLog

@@ -1,3 +1,8 @@
+2021-01-20  Alan Modra  <amodra@gmail.com>
+
+	* elf64-ppc.c (ppc64_elf_get_synthetic_symtab): Don't assume
+	section symbols are present.
+
 2021-01-18  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/27193

bfd/elf64-ppc.c

@@ -2299,7 +2299,8 @@ ppc64_elf_get_synthetic_symtab (bfd *abfd,
 	 sym->section directly.  With separate debug info files, the
 	 symbols will be extracted from the debug file while abfd passed
 	 to this function is the real binary.  */
-      if (strcmp (syms[i]->section->name, ".opd") == 0)
+      if ((syms[i]->flags & BSF_SECTION_SYM) != 0
+	  && strcmp (syms[i]->section->name, ".opd") == 0)
 	++i;
       codesecsym = i;