v3d: Fix input packing of .l for rounding/fdx/fdy.

Avoids a regression in
dEQP-GLES3.functional.shaders.derivate.fwidth.texture.* once we start
copy-propagating more input packs.

src/broadcom/qpu/qpu_pack.c

@@ -1095,7 +1095,7 @@ v3d_qpu_add_pack(const struct v3d_device_info *devinfo,
                 }
                 if (packed == 0)
                         return false;
-                opcode |= packed << 2;
+                opcode = (opcode & ~(1 << 2)) | packed << 2;
                 break;
         }
 

src/broadcom/qpu/tests/qpu_disasm.c

@@ -49,6 +49,7 @@ static const struct {
         { 33, 0x2011c89b402cc000ull, "fsub.norz  rf27, r4.abs, r1.abs; vfmul.ifa  rf34, r3.swp, r1" },
 
         { 33, 0xe01b42ab3bb063c0ull, "vfpack.andnc  rf43, rf15.l, r0.h; fmul.ifna  rf10.h, r4.l, r5.abs" },
+        { 33, 0x600b8b87fb4d1000ull, "fdx.ifnb  rf7.h, r1.l; fmul.pushn  rf46, r3.l, r2.abs" },
 
         /* small immediates */
         { 33, 0x5de24398bbdc6218ull, "vflb.andnn  rf24     ; fmul  rf14, -8, rf8.h" },