bpf: remove unhelpful "comptime" and fix union order
Insn.st() can be used with dynamic size just like Insn.stx(), which is
relevant in a code generation context.
using ImmOrReg caused an error as its fields were ordered differently than
Source.
1a0e6bcdb1bfredl committed on 9/15/2023, 8:05:52 AM· committed by Andrew Kelleyparentcba7e8a