Add #row_major matrix[R, C]T

As well as `#column_major matrix[R, C]T` as an alias for just `matrix[R, C]T`.
This is because some libraries require a row_major internal layout but still want to be used with row or major oriented vectors.

base/runtime/core.odin

@@ -177,6 +177,10 @@ Type_Info_Matrix :: struct {
 	row_count:    int,
 	column_count: int,
 	// Total element count = column_count * elem_stride
+	layout: enum u8 {
+		Column_Major, // array of column vectors
+		Row_Major,    // array of row vectors
+	},
 }
 Type_Info_Soa_Pointer :: struct {
 	elem: ^Type_Info,