Rollup merge of #119365 - nbdd0121:asm-goto, r=Amanieu

Add asm goto support to `asm!`

Tracking issue: #119364

This PR implements asm-goto support, using the syntax described in "future possibilities" section of [RFC2873](https://rust-lang.github.io/rfcs/2873-inline-asm.html#asm-goto).

Currently I have only implemented the `label` part, not the `fallthrough` part (i.e. fallthrough is implicit). This doesn't reduce the expressive though, since you can use label-break to get arbitrary control flow or simply set a value and rely on jump threading optimisation to get the desired control flow. I can add that later if deemed necessary.

r? ``@Amanieu``
cc ``@ojeda``

compiler/rustc_borrowck/src/lib.rs

@@ -723,7 +723,7 @@ impl<'cx, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx, R> for MirBorro
                 operands,
                 options: _,
                 line_spans: _,
-                destination: _,
+                targets: _,
                 unwind: _,
             } => {
                 for op in operands {
@@ -749,7 +749,8 @@ impl<'cx, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx, R> for MirBorro
                         }
                         InlineAsmOperand::Const { value: _ }
                         | InlineAsmOperand::SymFn { value: _ }
-                        | InlineAsmOperand::SymStatic { def_id: _ } => {}
+                        | InlineAsmOperand::SymStatic { def_id: _ }
+                        | InlineAsmOperand::Label { target_index: _ } => {}
                     }
                 }
             }