Squashed 'third_party/immer/' content from commit ad3e3556d

git-subtree-dir: third_party/immer
git-subtree-split: ad3e3556d38bb75966dd24c61a774970a7c7957e

BUILD

@@ -0,0 +1,11 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "immer",
+    include_prefix = "immer",
+    strip_include_prefix =
+        "immer",
+    hdrs = glob([
+        "immer/**/*.hpp",
+    ]),
+)