[gtk] (14 commits) ...Merge branch 'optimize-precompile' into 'main'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  f2d3d7e... builder: Avoid double string lookup in precompile (*)
  83dc126... builder: Use a string chunk for precompile (*)
  8b7d4b4... builder: Combine attribute name and value allocations (*)
  c6ecf02... builder: Embed text length in precompile (*)
  b962d37... builder: Use a reasonable default string size in precompile (*)
  1bfd0e5... builder: Use a GQueue in precompile (*)
  4ce07f4... builder: Reduce memory usage in precompile (*)
  8b228e7... builder: Use a flexible array for attributes in precompile (*)
  6c8b505... builder: Avoid g_hash_table_get_values() in precompile (*)
  9c12b58... builder: Remove root special case from precompile (*)
  fcb6ada... builder: Use g_slice_free_chain() for strings in precompile (*)
  c7afa54... builder: Drop irrelevant whitespace in precompile (*)
  c5bffb9... builder: Drop empty text chunks when precompiling (*)
  208769f... Merge branch 'optimize-precompile' into 'main'

(*) This commit already existed in another branch; no separate mail sent