v3d: Add support for register-allocating a ldunif to a QFILE_TEMP.

On V3D 4.x, we can use ldunifrf to load uniforms to any register, and this
will let us schedule the ldunif wherever we want in the program.

src/broadcom/compiler/v3d_compiler.h

@@ -476,6 +476,8 @@ vir_after_block(struct qblock *block)
 struct v3d_compiler {
         const struct v3d_device_info *devinfo;
         struct ra_regs *regs;
+        unsigned int reg_class_any[3];
+        unsigned int reg_class_r5[3];
         unsigned int reg_class_phys[3];
         unsigned int reg_class_phys_or_acc[3];
 };