[gcc r14-8404] RISC-V: Don't make Ztso imply A

[Patrick O'Neill]

https://gcc.gnu.org/g:0d1b0f2ad391217a43e9239ca017958f89e8f076

commit r14-8404-g0d1b0f2ad391217a43e9239ca017958f89e8f076
Author: Palmer Dabbelt <palmer@rivosinc.com>
Date:   Tue Dec 12 19:54:05 2023 -0800

    RISC-V: Don't make Ztso imply A
    
    I can't actually find anything in the ISA manual that makes Ztso imply
    A.  In theory the memory ordering is just a different thing that the set
    of availiable instructions (ie, Ztso without A would still imply TSO for
    loads and stores).  It also seems like a configuration that could be
    sane to build: without A it's all but impossible to write any meaningful
    multi-core code, and TSO is really cheap for a single core.
    
    That said, I think it's kind of reasonable to provide A to users asking
    for Ztso.  So maybe even if this was a mistake it's the right thing to
    do?
    
    gcc/ChangeLog:
    
            * common/config/riscv/riscv-common.cc (riscv_implied_info):
            Remove {"ztso", "a"}.

Diff:
---
 gcc/common/config/riscv/riscv-common.cc | 2 --
 1 file changed, 2 deletions(-)

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index 4da7f37303b..0a3c5cdfae5 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -96,8 +96,6 @@ static const riscv_implied_info_t riscv_implied_info[] =
   {"zks", "zksed"},
   {"zks", "zksh"},
 
-  {"ztso", "a"},
-
   {"v", "zvl128b"},
   {"v", "zve64d"},