patchShebangs: Allow for multiple arguments

It's tempting to think patchShebangs supports multiple arguments.
Without this patch it just silently ignores all but the first. Now it
patches the shebangs in all of its arguments.

Fixes: #57695

pkgs/build-support/setup-hooks/patch-shebangs.sh

@@ -9,8 +9,9 @@
 
 fixupOutputHooks+=(patchShebangsAuto)
 
-# Run patch shebangs on a directory.
-# patchShebangs [--build | --host] directory
+# Run patch shebangs on a directory or file.
+# Can take multiple paths as arguments.
+# patchShebangs [--build | --host] PATH...
 
 # Flags:
 # --build : Lookup commands available at build-time
@@ -31,9 +32,7 @@ patchShebangs() {
         shift
     fi
 
-    local dir="$1"
-
-    header "patching script interpreter paths in $dir"
+    header "patching script interpreter paths in $@"
     local f
     local oldPath
     local newPath
@@ -42,8 +41,6 @@ patchShebangs() {
     local oldInterpreterLine
     local newInterpreterLine
 
-    [ -e "$dir" ] || return 0
-
     local f
     while IFS= read -r -d $'\0' f; do
         isScript "$f" || continue
@@ -97,7 +94,7 @@ patchShebangs() {
                 rm "$timestamp"
             fi
         fi
-    done < <(find "$dir" -type f -perm -0100 -print0)
+    done < <(find "$@" -type f -perm -0100 -print0)
 
     stopNest
 }