sort build rules in folly/lang/, moving rule pretty

Summary:
The only reasonable high-level order for build rules is lexicographical. Apply to `folly/lang/`, specifically moving `pretty` around.

Extracting from {D68150927} by Orvid.

Reviewed By: Gownta

Differential Revision: D69288292

fbshipit-source-id: e782ad4b14ee2bc838a95086f2a6f62338abff83

folly/lang/BUCK

@@ -196,6 +196,15 @@ cpp_library(
     ],
 )
 
+cpp_library(
+    name = "pretty",
+    headers = ["Pretty.h"],
+    exported_deps = [
+        ":c_array",
+        "//folly:portability",
+    ],
+)
+
 cpp_library(
     name = "propagate_const",
     headers = ["PropagateConst.h"],
@@ -269,15 +278,6 @@ cpp_library(
     ],
 )
 
-cpp_library(
-    name = "pretty",
-    headers = ["Pretty.h"],
-    exported_deps = [
-        ":c_array",
-        "//folly:portability",
-    ],
-)
-
 cpp_library(
     name = "uncaught_exceptions",
     srcs = ["UncaughtExceptions.cpp"],

folly/lang/test/BUCK

@@ -173,6 +173,15 @@ cpp_unittest(
     ],
 )
 
+cpp_unittest(
+    name = "pretty_test",
+    srcs = ["PrettyTest.cpp"],
+    deps = [
+        "//folly/lang:pretty",
+        "//folly/portability:gtest",
+    ],
+)
+
 cpp_unittest(
     name = "propagate_const_test",
     srcs = ["PropagateConstTest.cpp"],
@@ -247,12 +256,3 @@ cpp_unittest(
         "//folly/portability:gtest",
     ],
 )
-
-cpp_unittest(
-    name = "pretty_test",
-    srcs = ["PrettyTest.cpp"],
-    deps = [
-        "//folly/lang:pretty",
-        "//folly/portability:gtest",
-    ],
-)