[llvm] [TargetInstrInfo] Enable instruction size verification by default (PR #221687)

[David Spickett via llvm-commits]

DavidSpickett wrote:

We have two test suite failures on Armv7 and 8 (32-bit). Both reduce to this:
```
$ cat /tmp/test.c
void a() {
  void *b;
  __builtin_longjmp(b, 1);
}
$ ./bin/clang -target armv8l-linux-gnueabi /tmp/test.c -o /dev/null
In function: a
Size mismatch for: Int_eh_sjlj_longjmp killed renamable $r0, killed renamable $r1, implicit-def dead $r7, implicit-def dead $lr, implicit-def dead $sp
Expected maximum size: 16
Actual size: 20
```

https://github.com/llvm/llvm-project/pull/221687