SpirvShader: Implement GLSLstd450Radians

Bug: b/126873455
Tests: dEQP-VK.glsl.builtin.precision.radians.*
Change-Id: Iae78dac21165967d305a54157f60d95d13de5984
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28649
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/Pipeline/SpirvShader.cpp b/src/Pipeline/SpirvShader.cpp
index aff801e..e028dc9 100644
--- a/src/Pipeline/SpirvShader.cpp
+++ b/src/Pipeline/SpirvShader.cpp
@@ -28,6 +28,8 @@
 
 namespace
 {
+	constexpr float PI = 3.141592653589793f;
+
 	rr::RValue<rr::Bool> AnyTrue(rr::RValue<sw::SIMD::Int> const &ints)
 	{
 		return rr::SignMask(ints) != 0;
@@ -3264,6 +3266,15 @@
 			}
 			break;
 		}
+		case GLSLstd450Radians:
+		{
+			auto degrees = GenericValue(this, routine, insn.word(5));
+			for (auto i = 0u; i < type.sizeInComponents; i++)
+			{
+				dst.move(i, degrees.Float(i) * SIMD::Float(PI / 180.0f));
+			}
+			break;
+		}
 		default:
 			UNIMPLEMENTED("Unhandled ExtInst %d", extInstIndex);
 		}