[gdb/testsuite] Handle for loop initial decl with gcc 4.8.5

When running test-case gdb.threads/schedlock-thread-exit.exp on a system with
system compiler gcc 4.8.5, I run into:
...
src/gdb/testsuite/gdb.threads/schedlock-thread-exit.c:33:3: error: \
  'for' loop initial declarations are only allowed in C99 mode
...

Fix this by:
- using -std=c99, or
- using -std=gnu99, in case that's required, or
- in the case of the jit test-cases, rewriting the for loops.

Tested on x86_64-linux, both with gcc 4.8.5 and gcc 7.5.0.

1 files changed, 4 insertions, 3 deletions

diff --git a/gdb/testsuite/gdb.base/jit-elf-util.h b/gdb/testsuite/gdb.base/jit-elf-util.h
index 80dfd0c..419a781 100644
--- a/gdb/testsuite/gdb.base/jit-elf-util.h
+++ b/gdb/testsuite/gdb.base/jit-elf-util.h
@@ -54,8 +54,8 @@ load_symbol (void *addr, const char *sym_name)
   ElfW (Addr) sym_new_addr = 0;
 
   /* Find `func_name` in symbol_table and return its address.  */
-
-  for (int i = 0; i < ehdr->e_shnum; ++i)
+  int i;
+  for (i = 0; i < ehdr->e_shnum; ++i)
     {
       if (shdr[i].sh_type == SHT_SYMTAB)
 	{
@@ -65,7 +65,8 @@ load_symbol (void *addr, const char *sym_name)
 	  char *const strtab
 	      = (char *) (addr + shdr[shdr[i].sh_link].sh_offset);
 
-	  for (ElfW (Sym) *p = symtab; p < symtab_end; ++p)
+	  ElfW (Sym) *p;
+	  for (p = symtab; p < symtab_end; ++p)
 	    {
 	      const char *s = strtab + p->st_name;
 	      if (strcmp (s, sym_name) == 0)