absl/status: Fix build on AIX

`_LINUX_SOURCE_COMPAT` needs to be defined to fix

    absl/status/status.cc:494:5: error: duplicate case value
      494 |     case ENOTEMPTY:   // Directory not empty
          |     ^~~~
    absl/status/status.cc:480:5: note: previously used here
      480 |     case EEXIST:         // File exists
          |     ^~~~

absl/status/CMakeLists.txt

@@ -25,6 +25,8 @@ absl_cc_library(
     "status_payload_printer.cc"
   COPTS
     ${ABSL_DEFAULT_COPTS}
+  DEFINES
+    "$<$<PLATFORM_ID:AIX>:_LINUX_SOURCE_COMPAT>"
   DEPS
     absl::atomic_hook
     absl::config