Ensure that Driver always runs against a consistent language

[TomAFrench]

Problem

When creating a Driver struct we must pass in an acvm::Language for the NodeInterner to use.

noir/crates/noirc_driver/src/lib.rs

Lines 28 to 32 in f304afc

	pub fn new(np_language: &acvm::Language) -> Self {
	let mut driver = Driver { context: Context::default() };
	driver.context.def_interner.set_language(np_language);
	driver
	}

When we call driver.into_compiled_program we pass in a acvm::Language again.

noir/crates/noirc_driver/src/lib.rs

Lines 147 to 155 in f304afc

	pub fn into_compiled_program(
	mut self,
	np_language: acvm::Language,
	show_ssa: bool,
	allow_warnings: bool,
	) -> Result<CompiledProgram, ReportedError> {
	self.check_crate(allow_warnings)?;
	self.compile_no_check(np_language, show_ssa, allow_warnings, None, true)
	}

This seems like it's opening up potential for inconsistent languages to be used which would cause unknown weirdness.

Solution

We should add a private field to Driver to track this language from construction time and stop allowing the language to be passed in to the methods.

Alternatives considered

Additional context