Adding missing C headers and Swift code for Vec<f32/f64> support

[rkreutz]

This PR adds support for Vec<f32>/Vec<f64> (it seems it was mostly some C headers and Swift code missing).

Rust code would look like:

#[swift_bridge::bridge]
mod ffi {
    #[swift_bridge(swift_repr = "struct")]
    struct SomeStruct {
        field: Vec<f32>,
    }

    extern "Rust" {
        fn do_something(val: SomeStruct) -> Vec<f32>;
    }
}

fn do_something(val: SomeStruct) -> Vec<f32> {
    /* do something */
}

On Swift side, Double and Float are now Vectorizable.

[rkreutz]

@chinedufn I couldn't find any tests for the other primitives Vec support, so I wasn't sure where to add tests (or if they are necessary). Please advise on how you'd like to proceed.

[chinedufn]

Thanks!

You can find a basic Vec<Primitive> test here

swift-bridge/SwiftRustIntegrationTestRunner/SwiftRustIntegrationTestRunnerTests/VecTests.swift

Lines 96 to 116 in c1fd717

	/// Verify that we can construct a RustVec of every primitive type.
	/// We tested all of the methods on two different primitives above to be sure that our
	/// functions that generate the pieces of the RustVec support aren't accidentally hard coded to
	/// only work for one type.
	/// Here we call the rest of the types, confident that if we can construct them then the rest of their
	/// methods will work since they worked for the other types above.
	func testConstructPrimitiveRustVecs() throws {
	XCTAssertEqual(RustVec<UInt8>().pop(), nil);
	XCTAssertEqual(RustVec<UInt16>().len(), 0);
	XCTAssertEqual(RustVec<UInt32>().len(), 0);
	XCTAssertEqual(RustVec<UInt64>().len(), 0);
	XCTAssertEqual(RustVec<UInt>().len(), 0);
	XCTAssertEqual(RustVec<Int8>().len(), 0);
	XCTAssertEqual(RustVec<Int16>().len(), 0);
	XCTAssertEqual(RustVec<Int32>().len(), 0);
	XCTAssertEqual(RustVec<Int64>().len(), 0);
	XCTAssertEqual(RustVec<Int>().len(), 0);
	XCTAssertEqual(RustVec<Bool>().len(), 0);
	}

[chinedufn]

We can delete these changes and change OptionDouble to OptionF64 here

swift-bridge/crates/swift-bridge-build/src/generate_core.rs

Line 88 in 20baa73

typedef struct __private__OptionF64 { double val; bool is_some; } __private__OptionDouble;

[rkreutz]

Yeah, I've thought the same, just wasn't sure if there was a reason for them to not be equal. Anyway, will do this change and add the tests. Cheers

[rkreutz]

Added tests 60af50d and renamed OptionDouble to OptionF64 6dd8e42

[chinedufn]

Thanks!!