Compile static libraries with optimization

[mmontag]

For subprojects where I have left static library build process intact (rather than building source directly in build-chip-core.js):

• libpsflib.a
• liblazyusf.a
• libfluidlite.a
• libxmp-lite.a ...And soon:
• libvgm-emu.a
• libvgm-utils.a
• libvgm-player.a

These have so far been compiled with whatever default settings. Size could be shaved off with compiler flag -Os.

For example, compiling libvgm with and without optimizations yields (by itself) a chip-core.wasm size of 538 KB and 687 KB respectively (22% reduction).