stdlib & Runtime: Replace atomicStore/Load stubs with builtins.

Swift SVN r32953

stdlib/public/core/Runtime.swift.gyb

@@ -122,10 +122,14 @@ func _stdlib_atomicCompareExchangeStrongInt${bits}(
     desired: UInt${bits}(bitPattern: desired))
 }
 
-@asmname("swift_stdlib_atomicStoreUInt${bits}")
+@transparent
+public // @testable
 func _swift_stdlib_atomicStoreUInt${bits}(
   object target: UnsafeMutablePointer<UInt${bits}>,
-  desired: UInt${bits})
+  desired: UInt${bits}) {
+
+  Builtin.atomicstore_seqcst_Int${bits}(target._rawValue, desired._value)
+}
 
 func _swift_stdlib_atomicStoreInt${bits}(
   object target: UnsafeMutablePointer<Int${bits}>,
@@ -136,9 +140,13 @@ func _swift_stdlib_atomicStoreInt${bits}(
 }
 
 @warn_unused_result
-@asmname("swift_stdlib_atomicLoadUInt${bits}")
+public // @testable
 func _swift_stdlib_atomicLoadUInt${bits}(
-  object target: UnsafeMutablePointer<UInt${bits}>) -> UInt${bits}
+  object target: UnsafeMutablePointer<UInt${bits}>) -> UInt${bits} {
+
+  let value = Builtin.atomicload_seqcst_Int${bits}(target._rawValue)
+  return UInt${bits}(value)
+}
 
 @warn_unused_result
 func _swift_stdlib_atomicLoadInt${bits}(
@@ -217,10 +225,14 @@ public func _swift_stdlib_atomicLoadInt(
 }
 
 @warn_unused_result
-@asmname("swift_stdlib_atomicLoadPtr")
+@transparent
+public // @testable
 func _swift_stdlib_atomicLoadPtrImpl(
   object target: UnsafeMutablePointer<COpaquePointer>
-) -> COpaquePointer
+) -> COpaquePointer {
+  let value = Builtin.atomicload_seqcst_RawPointer(target._rawValue)
+  return COpaquePointer(value)
+}
 
 @transparent
 @warn_unused_result

stdlib/public/runtime/Stubs.cpp

@@ -265,31 +265,6 @@ typedef enum {
   memory_order_seq_cst = 5
 } memory_order;
 
-extern "C" void swift_stdlib_atomicStoreUInt32(
-    _Atomic(uint32_t) * object, uint32_t desired) {
-  return __c11_atomic_store(object, desired, memory_order_seq_cst);
-}
-
-extern "C" void swift_stdlib_atomicStoreUInt64(
-    _Atomic(uint64_t) * object, uint64_t desired) {
-  return __c11_atomic_store(object, desired, memory_order_seq_cst);
-}
-
-extern "C" uint32_t swift_stdlib_atomicLoadUInt32(
-    _Atomic(uint32_t) * object) {
-  return __c11_atomic_load(object, memory_order_seq_cst);
-}
-
-extern "C" uint64_t swift_stdlib_atomicLoadUInt64(
-    _Atomic(uint64_t) * object) {
-  return __c11_atomic_load(object, memory_order_seq_cst);
-}
-
-extern "C" uintptr_t swift_stdlib_atomicLoadPtr(
-    _Atomic(uintptr_t) * object) {
-  return __c11_atomic_load(object, memory_order_seq_cst);
-}
-
 // fetch_add
 
 extern "C" uint32_t swift_stdlib_atomicFetchAddUInt32(