srcOnly: make the -source suffix optional

pkgs/build-support/src-only/default.nix

@@ -6,17 +6,27 @@
 #
 # > srcOnly pkgs.hello
 #
-attrs:
+{
+  noSuffix ? false,
+  ...
+}@attrs:
 let
-  args = if builtins.hasAttr "drvAttrs" attrs then attrs.drvAttrs else attrs;
-  name = if builtins.hasAttr "name" args then args.name else "${args.pname}-${args.version}";
+  args = if attrs ? drvAttrs then attrs.drvAttrs else attrs;
+  name = if args ? name then args.name else "${args.pname}-${args.version}";
 in
-stdenv.mkDerivation (args // {
-  name = "${name}-source";
-  installPhase = "cp -pr --reflink=auto -- . $out";
-  outputs = [ "out" ];
-  separateDebugInfo = false;
-  dontUnpack = false;
-  dontInstall = false;
-  phases = ["unpackPhase" "patchPhase" "installPhase"];
-})
+stdenv.mkDerivation (
+  args
+  // {
+    name = if noSuffix then name else "${name}-source";
+    installPhase = "cp -pr --reflink=auto -- . $out";
+    outputs = [ "out" ];
+    separateDebugInfo = false;
+    dontUnpack = false;
+    dontInstall = false;
+    phases = [
+      "unpackPhase"
+      "patchPhase"
+      "installPhase"
+    ];
+  }
+)