macos: set LC_MAIN entrypoint correctly
macos: set LC_MAIN entrypoint correctly

to the file offset of 'main' not simply to the start of TEXT.

mirror/tinycc,mingodad/tinycc,mirror/tinycc,mingodad/tinycc,mingodad/tinycc,mingodad/tinycc,mirror/tinycc,mirror/tinycc