Update abseil-cpp to a new upstream

Actually update to bf7fc9986e20f664958fc227547fd8d2fdcf863e

Change #754 didn't completely do this.

This makes the rest of the sources match optional, which was imported at
this change in #1083.

Also add:
  absl/types/optional_test.cc
  absl/types/CMakeLists.txt
  absl/utility/CMakeLists.txt

1 files changed, 19 insertions, 2 deletions

diff --git a/Firestore/third_party/abseil-cpp/absl/base/attributes.h b/Firestore/third_party/abseil-cpp/absl/base/attributes.h
index 4e1fc8b..a4ec7e7 100644
--- a/Firestore/third_party/abseil-cpp/absl/base/attributes.h
+++ b/Firestore/third_party/abseil-cpp/absl/base/attributes.h
@@ -527,17 +527,34 @@
 #define ABSL_ATTRIBUTE_PACKED
 #endif
 
+// ABSL_ATTRIBUTE_FUNC_ALIGN
+//
+// Tells the compiler to align the function start at least to certain
+// alignment boundary
+#if ABSL_HAVE_ATTRIBUTE(aligned) || (defined(__GNUC__) && !defined(__clang__))
+#define ABSL_ATTRIBUTE_FUNC_ALIGN(bytes) __attribute__((aligned(bytes)))
+#else
+#define ABSL_ATTRIBUTE_FUNC_ALIGN(bytes)
+#endif
+
 // ABSL_CONST_INIT
 //
 // A variable declaration annotated with the `ABSL_CONST_INIT` attribute will
 // not compile (on supported platforms) unless the variable has a constant
 // initializer. This is useful for variables with static and thread storage
 // duration, because it guarantees that they will not suffer from the so-called
-// "static init order fiasco".
+// "static init order fiasco".  Prefer to put this attribute on the most visible
+// declaration of the variable, if there's more than one, because code that
+// accesses the variable can then use the attribute for optimization.
 //
 // Example:
 //
-//   ABSL_CONST_INIT static MyType my_var = MakeMyType(...);
+//   class MyClass {
+//    public:
+//     ABSL_CONST_INIT static MyType my_var;
+//   };
+//
+//   MyType MyClass::my_var = MakeMyType(...);
 //
 // Note that this attribute is redundant if the variable is declared constexpr.
 #if ABSL_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization)