KOS_OP_VAR_CLEAR3

• Style: EXTRA (VAR, VAR, VAR, NOARG). Row = 3 constant pool name indices (post-compile).

• Stack: No stack effect. Clear the 3 names in row order, as 3 VAR_CLEAR would; an already empty one stays empty.

• Compiler form: Never emitted by specials. Produced only by ByteCodeProcessor.pack_runs, which combines a run of consecutive VAR_CLEAR instructions (quads first, then one triple or one pair).