SpirvShader: Implement GLSLstd450Acosh

Bug: b/126873455
Tests: dEQP-VK.glsl.builtin.precision.acosh.*
Change-Id: Id02fae0c7020ee83cb612f9370cdbb5c4dc31af1
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28693
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>

src/Reactor/Reactor.hpp

diff --git a/src/Reactor/Reactor.hpp b/src/Reactor/Reactor.hpp
index ffbd7c8..7609307 100644
--- a/src/Reactor/Reactor.hpp
+++ b/src/Reactor/Reactor.hpp
@@ -2218,6 +2218,7 @@
 	RValue<Float4> Cosh(RValue<Float4> x);
 	RValue<Float4> Tanh(RValue<Float4> x);
 	RValue<Float4> Asinh(RValue<Float4> x);
+	RValue<Float4> Acosh(RValue<Float4> x);
 
 	template<class T>
 	class Pointer : public LValue<Pointer<T>>