Fill in boilerplate for Intel and ARM targets.

The intel, arm32, and arm32 targets were only defined in the meta
language previously. Add Rust implementations too.

This is mostly boilerplate, except for the unit tests in the
registers.rs files.

lib/cretonne/src/isa/arm64/mod.rs

@@ -0,0 +1,66 @@
+//! ARM 64-bit Instruction Set Architecture.
+
+pub mod settings;
+mod enc_tables;
+mod registers;
+
+use super::super::settings as shared_settings;
+use isa::enc_tables::{lookup_enclist, general_encoding};
+use isa::Builder as IsaBuilder;
+use isa::{TargetIsa, RegInfo, Encoding, Legalize};
+use ir::{InstructionData, DataFlowGraph};
+
+#[allow(dead_code)]
+struct Isa {
+    shared_flags: shared_settings::Flags,
+    isa_flags: settings::Flags,
+}
+
+/// Get an ISA builder for creating ARM64 targets.
+pub fn isa_builder() -> IsaBuilder {
+    IsaBuilder {
+        setup: settings::builder(),
+        constructor: isa_constructor,
+    }
+}
+
+fn isa_constructor(shared_flags: shared_settings::Flags,
+                   builder: &shared_settings::Builder)
+                   -> Box<TargetIsa> {
+    Box::new(Isa {
+        isa_flags: settings::Flags::new(&shared_flags, builder),
+        shared_flags: shared_flags,
+    })
+}
+
+impl TargetIsa for Isa {
+    fn name(&self) -> &'static str {
+        "arm64"
+    }
+
+    fn flags(&self) -> &shared_settings::Flags {
+        &self.shared_flags
+    }
+
+    fn register_info(&self) -> &RegInfo {
+        &registers::INFO
+    }
+
+    fn encode(&self, _: &DataFlowGraph, inst: &InstructionData) -> Result<Encoding, Legalize> {
+        lookup_enclist(inst.first_type(),
+                       inst.opcode(),
+                       &enc_tables::LEVEL1_A64[..],
+                       &enc_tables::LEVEL2[..])
+            .and_then(|enclist_offset| {
+                general_encoding(enclist_offset,
+                                 &enc_tables::ENCLISTS[..],
+                                 |instp| enc_tables::check_instp(inst, instp),
+                                 |isap| self.isa_flags.numbered_predicate(isap as usize))
+                    .ok_or(Legalize::Expand)
+            })
+    }
+
+    fn recipe_names(&self) -> &'static [&'static str] {
+        &enc_tables::RECIPE_NAMES[..]
+    }
+}