Updated Makefile to use the LD environment variable for the linker if it is set, otherwise just use ld from $PATH
Update Makefile to use the OBJCOPY environment variable for the objcopy program if it is set, otherwise just use objcopy from $PATH
Use New And Improved(TM) nasm syntax for float and binary constants, to make it work with more recent nasms
Update nasm command-line syntax to work with more recent nasm versions
Update Makefile to generalize building .bc and .o files
Update rustc invocation to use New And Improved(TM) --emit bc flag instead of the old --emit-llvm flag, and also remove --lib
Update rust-core to latest version
Remove unnecessary parentheses around if expressions
Declare arguments to free() and realloc() as unused
Unused variables--