gnu: Add abseil-cpp-20211102.0.

* gnu/packages/cpp.scm (abseil-cpp-20211102.0): New variable.

gnu/packages/cpp.scm

@@ -1070,6 +1070,29 @@ augment the C++ standard library.  The Abseil library code is collected from
 Google's C++ code base.")
     (license license:asl2.0)))
 
+;; This is for grpc-for-python-grpcio; keep this in sync with its actual
+;; requirements.
+(define-public abseil-cpp-20211102.0
+  (let ((base abseil-cpp-20200923.3))
+    (package
+      (inherit base)
+      (name "abseil-cpp")
+      (version "20211102.0")
+      (source (origin
+                (method git-fetch)
+                (uri (git-reference
+                      (url "https://github.com/abseil/abseil-cpp")
+                      (commit "215105818dfde3174fe799600bb0f3cae233d0bf")))
+                (file-name (git-file-name name version))
+                (sha256
+                 (base32
+                  "028vlxpmh65kb7s0cpba38qcwk1abyn5br0ffhvvjjh97vld69di"))))
+      (arguments
+       (substitute-keyword-arguments (package-arguments base)
+         ((#:tests? _ #false) #false)
+         ((#:configure-flags flags)
+          #~(cons* "-DCMAKE_CXX_STANDARD=11" #$flags)))))))
+
 (define-public abseil-cpp
   (let ((base abseil-cpp-20200923.3))
     (package