[BPF] Report an warning if certain insn imm operand cannot fit in 32bit (#142989)

Ihor Solodrai reported a case ([1]) where gcc reports an error but clang
ignores that error and proceeds to generate incorrect code. More
specifically, the problematic code looks like:
   if r1 == 0xcafefeeddeadbeef goto <label>

Here, 0xcafefeeddeadbeef needs to be encoded in a 32-bit imm field
of the insns and the 32-bit imm allows sign extenstion to 64-bit imm.
Obviously, 0xcafefeeddeadbeef cannot encode properly.

The compilation failed for gcc with the following error:
  Error: immediate out of range, shall fit in 32 bits

Given a 64-bit imm value, converting to the proper 32-bit imm value
must satisfy the following 64-bit patterns:
  00000000 00000000 00000000 00000000 xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
  11111111 11111111 11111111 11111111 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx

So if the top 32-bits is 0 or the top 33-bits is 0x1ffffffff, then the 64-bit imm
value can be truncated into proper 32-bit imm. Otherwise, a warning
message, the same as gcc, will be issued. If -Werror is enabled during
compilation, the warning will turn into an error.

[1] https://lore.kernel.org/bpf/70affb12-327b-4882-bd1d-afda8b8c6f56@linux.dev/

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