Make fixes, improvements, and chibicc python bindings

- python now mixes audio 10x faster
- python octal notation is restored
- chibicc now builds code 3x faster
- chibicc now has help documentation
- chibicc can now generate basic python bindings
- linenoise now supports some paredit-like features

See #141

third_party/chibicc/README.cosmo

@@ -6,6 +6,7 @@ which is great, considering it's a 220kb αcτµαlly pδrταblε εxεcµταb
 
 local enhancements
 
+- add assembler
 - support dce
 - support gnu asm
 - support __int128
@@ -24,6 +25,7 @@ local enhancements
 - reduce #lines of generated assembly by a third
 - reduce #bytes of generated binary by a third
 - report divide errors in constexprs
+- use perfect hash table for keywords
 
 local bug fixes