Move library crates under 'lib/'.

Give these crates each a more standard directory layout with sources in
a 'src' sub-sirectory and Cargo.toml in the top lib/foo directory.

Add license and description fields to each.

The build script for the cretonne crate now lives in
'lib/cretonne/build.rs' separating it from the normal library sources
under 'lib/cretonne/src'.

lib/reader/src/isaspec.rs

@@ -0,0 +1,49 @@
+//! Parsed representation of `set` and `isa` commands.
+//!
+//! A test case file can contain `set` commands that set ISA-independent settings, and it can
+//! contain `isa` commands that select an ISA and applies ISA-specific settings.
+//!
+//! If a test case file contains `isa` commands, the tests will only be run against the specified
+//! ISAs. If the file contains no `isa` commands, the tests will be run against all supported ISAs.
+
+use cretonne::settings::{Flags, Configurable, Error as SetError};
+use cretonne::isa::TargetIsa;
+use error::{Result, Location};
+use testcommand::TestOption;
+
+/// The ISA specifications in a `.cton` file.
+pub enum IsaSpec {
+    /// The parsed file does not contain any `isa` commands, but it may contain `set` commands
+    /// which are reflected in the finished `Flags` object.
+    None(Flags),
+
+    /// The parsed file does contains `isa` commands.
+    /// Each `isa` command is used to configure a `TargetIsa` trait object.
+    Some(Vec<Box<TargetIsa>>),
+}
+
+/// Parse an iterator of command line options and apply them to `config`.
+pub fn parse_options<'a, I>(iter: I, config: &mut Configurable, loc: &Location) -> Result<()>
+    where I: Iterator<Item = &'a str>
+{
+    for opt in iter.map(TestOption::new) {
+        match opt {
+            TestOption::Flag(name) => {
+                match config.set_bool(name, true) {
+                    Ok(_) => {}
+                    Err(SetError::BadName) => return err!(loc, "unknown flag '{}'", opt),
+                    Err(_) => return err!(loc, "not a boolean flag: '{}'", opt),
+                }
+            }
+            TestOption::Value(name, value) => {
+                match config.set(name, value) {
+                    Ok(_) => {}
+                    Err(SetError::BadName) => return err!(loc, "unknown setting '{}'", opt),
+                    Err(SetError::BadType) => return err!(loc, "invalid setting type: '{}'", opt),
+                    Err(SetError::BadValue) => return err!(loc, "invalid setting value: '{}'", opt),
+                }
+            }
+        }
+    }
+    Ok(())
+}