aarch64: Fix bogus type punning in parse_barrier() [PR26699]

This patch fixes a bogus use of type punning in parse_barrier() which
was causing an assembly failure on big endian LP64 hosts when attempting
to assemble "isb sy" for AArch64.

The type of the entries in aarch64_barrier_opt_hsh is
aarch64_name_value_pair. We were incorrectly casting this to the
locally-defined asm_barrier_opt which has a wider type (on LP64) for the
second member. This happened to work on little-endian hosts but fails on
LP64 big endian.

The fix is to use the correct type in parse_barrier(). This makes the
locally-defined asm_barrier_opt redundant, so remove it.

gas/ChangeLog:

	* config/tc-aarch64.c (asm_barrier_opt): Delete.
	(parse_barrier): Fix bogus type punning.
	* testsuite/gas/aarch64/system.d: Update disassembly.
	* testsuite/gas/aarch64/system.s: Add isb sy test.

1 files changed, 1 insertions, 7 deletions

diff --git a/gas/config/tc-aarch64.c b/gas/config/tc-aarch64.c
index 4bcfa05..fac571e 100644
--- a/gas/config/tc-aarch64.c
+++ b/gas/config/tc-aarch64.c
@@ -250,12 +250,6 @@ set_fatal_syntax_error (const char *error)
 typedef struct
 {
   const char *template;
-  unsigned long value;
-} asm_barrier_opt;
-
-typedef struct
-{
-  const char *template;
   uint32_t value;
 } asm_nzcv;
 
@@ -3993,7 +3987,7 @@ static int
 parse_barrier (char **str)
 {
   char *p, *q;
-  const asm_barrier_opt *o;
+  const struct aarch64_name_value_pair *o;
 
   p = q = *str;
   while (ISALPHA (*q))