SpirvShader: Implement GLSLstd450Sin

Bug: b/126873455
Tests: dEQP-VK.glsl.builtin.precision.sin.*
Change-Id: Iec96b2a235534fbc5b76c699a6b62679b75582ca
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28668
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/Reactor/Reactor.hpp b/src/Reactor/Reactor.hpp
index bb32a46..41e15c8 100644
--- a/src/Reactor/Reactor.hpp
+++ b/src/Reactor/Reactor.hpp
@@ -2206,6 +2206,10 @@
 	RValue<Float4> Floor(RValue<Float4> x);
 	RValue<Float4> Ceil(RValue<Float4> x);
 
+	// Trigonometric functions
+	// TODO: Currentlhy unimplemented for Subzero.
+	RValue<Float4> Sin(RValue<Float4> x);
+
 	template<class T>
 	class Pointer : public LValue<Pointer<T>>
 	{