Fix some (MSVC) compiler warnings

irr/include/irrMath.h

@@ -25,7 +25,7 @@ constexpr f64 ROUNDING_ERROR_f64 = 0.00000001;
 #undef PI
 #endif
 //! Constant for PI.
-constexpr f32 PI = M_PI;
+constexpr f32 PI = static_cast<f32>(M_PI);
 
 #ifdef PI64 // make sure we don't collide with a define
 #undef PI64

irr/src/CGLTFMeshFileLoader.cpp

@@ -549,12 +549,10 @@ void SelfType::MeshExtractor::deferAddMesh(
 
 static core::matrix4 loadTransform(const tiniergltf::Node::Matrix &m, SkinnedMesh::SJoint *joint)
 {
-	// Note: Under the hood, this casts these doubles to floats.
-	core::matrix4 mat = convertHandedness(core::matrix4(
-			m[0], m[1], m[2], m[3],
-			m[4], m[5], m[6], m[7],
-			m[8], m[9], m[10], m[11],
-			m[12], m[13], m[14], m[15]));
+	core::matrix4 mat;
+	for (size_t i = 0; i < m.size(); ++i)
+		mat[i] = static_cast<f32>(m[i]);
+	mat = convertHandedness(mat);
 
 	// Decompose the matrix into translation, scale, and rotation.
 	joint->Animatedposition = mat.getTranslation();

irr/src/OpenGL/ExtensionHandler.h

@@ -166,7 +166,7 @@ public:
 	inline void irrGlObjectLabel(GLenum identifier, GLuint name, const char *label)
 	{
 		if (KHRDebugSupported) {
-			u32 len = strlen(label);
+			u32 len = static_cast<u32>(strlen(label));
 			// Since our texture strings can get quite long we also truncate
 			// to a hardcoded limit of 82
 			len = std::min(len, std::min(MaxLabelLength, 82U));