std.builtin: make atomic order fields lowercase

compile_errors/atomic_orderings_of_atomicStore_Acquire_or_AcqRel.zig

@@ -1,10 +1,10 @@
 export fn entry() void {
  var x: u32 = 0;
- @atomicStore(u32, &x, 1, .Acquire);
+ @atomicStore(u32, &x, 1, .acquire);
 }
 
 // error
 // backend=stage2
 // target=native
 //
-// :3:31: error: @atomicStore atomic ordering must not be Acquire or AcqRel
+// :3:31: error: @atomicStore atomic ordering must not be acquire or acq_rel

compile_errors/atomic_orderings_of_cmpxchg-failure_stricter_than_success.zig

@@ -1,7 +1,7 @@
 const AtomicOrder = @import("std").builtin.AtomicOrder;
 export fn f() void {
  var x: i32 = 1234;
- while (!@cmpxchgWeak(i32, &x, 1234, 5678, AtomicOrder.Monotonic, AtomicOrder.SeqCst)) {}
+ while (!@cmpxchgWeak(i32, &x, 1234, 5678, AtomicOrder.monotonic, AtomicOrder.seq_cst)) {}
 }
 
 // error

compile_errors/atomic_orderings_of_cmpxchg-success_Monotonic_or_stricter.zig

@@ -1,11 +1,11 @@
 const AtomicOrder = @import("std").builtin.AtomicOrder;
 export fn f() void {
  var x: i32 = 1234;
- while (!@cmpxchgWeak(i32, &x, 1234, 5678, AtomicOrder.Unordered, AtomicOrder.Unordered)) {}
+ while (!@cmpxchgWeak(i32, &x, 1234, 5678, AtomicOrder.unordered, AtomicOrder.unordered)) {}
 }
 
 // error
 // backend=stage2
 // target=native
 //
-// :4:58: error: success atomic ordering must be Monotonic or stricter
+// :4:58: error: success atomic ordering must be monotonic or stricter

compile_errors/atomic_orderings_of_fence_Acquire_or_stricter.zig

@@ -1,9 +1,9 @@
 export fn entry() void {
- @fence(.Monotonic);
+ @fence(.monotonic);
 }
 
 // error
 // backend=stage2
 // target=native
 //
-// :2:13: error: atomic ordering must be Acquire or stricter
+// :2:13: error: atomic ordering must be acquire or stricter

compile_errors/atomicrmw_with_bool_op_not_.Xchg.zig

@@ -1,6 +1,6 @@
 export fn entry() void {
  var x = false;
- _ = @atomicRmw(bool, &x, .Add, true, .SeqCst);
+ _ = @atomicRmw(bool, &x, .Add, true, .seq_cst);
 }
 
 // error

compile_errors/atomicrmw_with_enum_op_not_.Xchg.zig

@@ -6,7 +6,7 @@ export fn entry() void {
  d,
  };
  var x: E = .a;
- _ = @atomicRmw(E, &x, .Add, .b, .SeqCst);
+ _ = @atomicRmw(E, &x, .Add, .b, .seq_cst);
 }
 
 // error

compile_errors/atomicrmw_with_float_op_not_.Xchg_.Add_.Sub_.Max_or_.Min.zig

@@ -1,6 +1,6 @@
 export fn entry() void {
  var x: f32 = 0;
- _ = @atomicRmw(f32, &x, .And, 2, .SeqCst);
+ _ = @atomicRmw(f32, &x, .And, 2, .seq_cst);
 }
 
 // error

compile_errors/cmpxchg_with_float.zig

@@ -1,6 +1,6 @@
 export fn entry() void {
  var x: f32 = 0;
- _ = @cmpxchgWeak(f32, &x, 1, 2, .SeqCst, .SeqCst);
+ _ = @cmpxchgWeak(f32, &x, 1, 2, .seq_cst, .seq_cst);
 }
 
 // error

compile_errors/passing_a_not-aligned-enough_pointer_to_cmpxchg.zig

@@ -1,7 +1,7 @@
 const AtomicOrder = @import("std").builtin.AtomicOrder;
 export fn entry() bool {
  var x: i32 align(1) = 1234;
- while (!@cmpxchgWeak(i32, &x, 1234, 5678, AtomicOrder.SeqCst, AtomicOrder.SeqCst)) {}
+ while (!@cmpxchgWeak(i32, &x, 1234, 5678, AtomicOrder.seq_cst, AtomicOrder.seq_cst)) {}
  return x == 5678;
 }