Move baseline updates over to the architecture-independent file

Author: DougGregor

test/api-digester/Outputs/stability-stdlib-source-base.swift.expected

@@ -360,3 +360,18 @@ Func ContiguousArray.withUnsafeBufferPointer(_:) is now without @rethrows
 Func ContiguousArray.withUnsafeMutableBufferPointer(_:) has generic signature change from <Element, R> to <Element, R, E where E : Swift.Error>
 Func ContiguousArray.withUnsafeMutableBufferPointer(_:) has parameter 0 type change from (inout Swift.UnsafeMutableBufferPointer<Element>) throws -> R to (inout Swift.UnsafeMutableBufferPointer<Element>) throws(E) -> R
 Func ContiguousArray.withUnsafeMutableBufferPointer(_:) is now without @rethrows
+
+// Adoption of @unsafe
+Func unsafeBitCast(_:to:) is now with @unsafe
+Func unsafeDowncast(_:to:) is now with @unsafe
+Struct OpaquePointer is now with @unsafe
+Struct Unmanaged is now with @unsafe
+Struct UnsafeBufferPointer is now with @unsafe
+Struct UnsafeMutableBufferPointer is now with @unsafe
+Struct UnsafeMutablePointer is now with @unsafe
+Struct UnsafeMutableRawBufferPointer is now with @unsafe
+Struct UnsafeMutableRawPointer is now with @unsafe
+Struct UnsafePointer is now with @unsafe
+Struct UnsafeRawBufferPointer is now with @unsafe
+Struct UnsafeRawPointer is now with @unsafe
+Var Optional.unsafelyUnwrapped is now with @unsafe

test/api-digester/Outputs/stability-stdlib-source-x86_64.swift.expected

@@ -3,18 +3,3 @@
 // NOTE: Most differences from the baseline are common across all architectures
 // should go into stability-stdlib-source-base.swift.expected. Only capture
 // x86_64-specific differences from the baseline here.
-
-// Adoption of @unsafe
-Func unsafeBitCast(_:to:) is now with @unsafe
-Func unsafeDowncast(_:to:) is now with @unsafe
-Struct OpaquePointer is now with @unsafe
-Struct Unmanaged is now with @unsafe
-Struct UnsafeBufferPointer is now with @unsafe
-Struct UnsafeMutableBufferPointer is now with @unsafe
-Struct UnsafeMutablePointer is now with @unsafe
-Struct UnsafeMutableRawBufferPointer is now with @unsafe
-Struct UnsafeMutableRawPointer is now with @unsafe
-Struct UnsafePointer is now with @unsafe
-Struct UnsafeRawBufferPointer is now with @unsafe
-Struct UnsafeRawPointer is now with @unsafe
-Var Optional.unsafelyUnwrapped is now with @unsafe