Instructions that produce more than one result complicate
optimizations. get_list/3 is one of two instructions that
produce multiple results (get_map_elements/3 is the other).

Introduce the get_hd/2 and get_tl/2 instructions
that return the head and tail of a cons cell, respectively,
and use it internally in all optimization passes.

For efficiency, we still want to use get_list/3 if both
head and tail are used, so we will translate matching pairs
of get_hd and get_tl back to get_list instructions.

The compiler option 'deterministic' was only recognized when given
as an option to the compiler, not when it was specified in a
-compile() attribute in the source file.

https://bugs.erlang.org/browse/ERL-498

Also test other options that turns off certain optimizations or
instruction sets.

The new chunk stores atoms encoded in UTF-8.

beam_lib has also been modified to handle the new
'utf8_atoms' attribute while the 'atoms' attribute
may be a missing chunk from now on.

The binary_to_atom/2 BIF can now encode any utf8
binary with up to 255 characters.

The list_to_atom/1 BIF can now accept codepoints
higher than 255 with up to 255 characters (thanks
to Björn Gustavsson).

missing_testheap/1 is no longer relevant for the following reasons:

1) Because of the literal pool introduced in R12, no test_heap
   instructions are needed in the guards.

2) beam_validator would abort the compilation if any needed test_heap
   instructions were missing.

The two bad record usage test cases in compile_SUITE do not
belong there, as the errors are detected in erl_lint. Move the
test to the erl_lint_SUITE.

Cover more code in v3_core.