Do not sort after subtraction.

This allows labels/strings to remain in their original order.

Test: go test bazel tests
Change-Id: I69f575df9e4a358fee4392ae48edf4550e463efb
diff --git a/bp2build/cc_library_conversion_test.go b/bp2build/cc_library_conversion_test.go
index 76f83e7..236dec4 100644
--- a/bp2build/cc_library_conversion_test.go
+++ b/bp2build/cc_library_conversion_test.go
@@ -1669,21 +1669,21 @@
     srcs = ["base.cpp"] + select({
         "//build/bazel/platforms/os:android": [
             "android.cpp",
-            "bionic.cpp",
             "linux.cpp",
+            "bionic.cpp",
         ],
         "//build/bazel/platforms/os:darwin": ["darwin.cpp"],
         "//build/bazel/platforms/os:linux": [
-            "linux.cpp",
             "linux_glibc.cpp",
+            "linux.cpp",
         ],
         "//build/bazel/platforms/os:linux_bionic": [
-            "bionic.cpp",
             "linux.cpp",
+            "bionic.cpp",
         ],
         "//build/bazel/platforms/os:linux_musl": [
-            "linux.cpp",
             "linux_musl.cpp",
+            "linux.cpp",
         ],
         "//build/bazel/platforms/os:windows": ["windows.cpp"],
         "//conditions:default": [],