Structs, arrays, owned strings, memory model, modules, debug info

- struct with default values; constructors Point(1, 2) / Point(x: 1); field access, auto-deref through pointers
- []T arrays with bounds checks, literals, for-each, push/pop/insert/remove/clear/resize/find/contains/join/slice/reverse/sort
- str carries its length: .len, s[i], +, comparison, sub/find/split/trim/upper/lower/replace/repeat/bytes, str(x), int(s), float(s)
- Memory: values own their memory and are freed at the end of their block; assignment copies, temporaries move;
  parameters are lent and only copied when the function changes them; defer; new()/free() for manual heap memory
- input(), read_file/write_file/file_exists, exit(), fn main([]str args)
- Finch modules: import name, module.fn(), module.Struct
- C structs from headers (fields, fixed arrays, nested); passed and returned by value with the System V x86-64 ABI;
  addr(fn) gives C a callback
- link "file.c" compiles and links your own C code
- -g emits DWARF debug info (gdb/lldb)
- Small C runtime (runtime/finch_rt.c) embedded in the compiler, cached in ~/.cache/finch
- Tests: 58, all clean under valgrind (MEMCHECK=1 tests/run.sh)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.20)
-project(finch VERSION 1.0.0 LANGUAGES CXX)
+project(finch VERSION 2.0.0 LANGUAGES CXX)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
@@ -13,9 +13,19 @@ add_executable(finch
     src/lexer.cpp
     src/parser.cpp
     src/codegen.cpp
+    src/codegen_types.cpp
+    src/codegen_builtins.cpp
+    src/abi.cpp
     src/cimport.cpp
 )
 
+# The runtime (runtime/finch_rt.c) is embedded into the compiler as a string;
+# finch compiles it once into ~/.cache/finch and links it into every program.
+set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${CMAKE_SOURCE_DIR}/runtime/finch_rt.c)
+file(READ ${CMAKE_SOURCE_DIR}/runtime/finch_rt.c FINCH_RT_SOURCE)
+file(WRITE ${CMAKE_BINARY_DIR}/rt_source.inc "static const char *kRuntimeSource = R\"FINCHRT(${FINCH_RT_SOURCE})FINCHRT\";\n")
+target_include_directories(finch PRIVATE ${CMAKE_BINARY_DIR})
+
 # libclang reads C headers for `import "stdio.h"`
 find_path(LIBCLANG_INCLUDE clang-c/Index.h HINTS ${LLVM_INCLUDE_DIRS})
 find_library(LIBCLANG NAMES clang libclang HINTS ${LLVM_LIBRARY_DIRS})