freedreno/ir3: don't cp absneg into meta:fi

If using a fanin (collect) to collect of consecutive registers together,
we can CP mov's into the fanin, but not (abs) or (neg).  No places that
allow those modifiers are consuming a fanin anyways.  But this caused an
absneg to be lost between a ldgb and stgb for shaders like:

  outputs[n] = abs(input[n])

Signed-off-by: Rob Clark <robdclark@gmail.com>

src/gallium/drivers/freedreno/ir3/ir3_cp.c

@@ -543,6 +543,10 @@ instr_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr)
 		if (reg->flags & IR3_REG_ARRAY)
 			continue;
 
+		/* Don't CP absneg into meta instructions, that won't end well: */
+		if (is_meta(instr) && (src->opc != OPC_MOV))
+			continue;
+
 		reg_cp(ctx, instr, reg, n);
 	}