* Reorganize the global value kinds.
This:
- renames "deref" global values to "load" and gives it a offset that works
like the "load" instructions' does
- adds an explicit "iadd_imm" global value kind, which replaces the
builtin iadd in "vmctx" and "deref" global values.
- also renames "globalsym" to "symbol"
This makes several changes:
- It adds an index_type to heap declarations, allowing heaps to specify the
type for indexing. This also anticipates 64-bit heap support.
- It adds a memory_type to deref global values, allowing deref globals to
have types other than pointers. This is used to allow the bound variable
in dynamic heaps to have type i32, to match the index type in heaps
with i32 index type.
- And, it fixes heap legalization to do the bounds check in the heap's
index type.
* Remove reserved_reg functionality.
This wasn't implemented, and if we need it in the future, it seems like
it would be better to extend the concept of global values to cover this.
* Use GlobalValue::reserved_value() for sentinal values.
The individual crates are published separately from the main repository
on crates.io. To ensure that a copy of the LICENSE file accompanies all
published copies of the code, give each crate its own LICENSE file.
Since Location is basically just a usize, and wasmparser::Type is an
enum, and both are copiable, this passes them down by value instead of
by reference, as suggested by Clippy.
In the text format, allow aliases to be defined multiple times, as long
as they're always aliasing the same value.
write.rs is already emitting redundant aliases, because it emits them at
their uses, so this change allows the parser to be able to parse such
code.
This switches from a custom list of architectures to use the
target-lexicon crate.
- "set is_64bit=1; isa x86" is replaced with "target x86_64", and
similar for other architectures, and the `is_64bit` flag is removed
entirely.
- The `is_compressed` flag is removed too; it's no longer being used to
control REX prefixes on x86-64, ARM and Thumb are separate
architectures in target-lexicon, and we can figure out how to
select RISC-V compressed encodings when we're ready.
