Support for lowering `goto` dialect into llvm IR

[kumarak]

Prerequisites

• I have read the documentation and the proposed feature is not implemented.

Description

Vast IRsToLLVM pass does not support replacement of high-level goto dialect and it is marked illegal. I see the following error while generating llvm ir from code snippet containing goto.

test.c:6:5: error: unexpected error: failed to legalize operation 'hl.goto' that was explicitly marked illegal
    goto basic_0;
    ^
test.c:6:5: error: unexpected note: see current operation: "hl.goto"(%0) : (!hl.label) -> ()
    goto basic_0;
    ^
// -----// IR Dump After IRsToLLVM Failed (vast-irs-to-llvm) //----- //
module {
  core.module @"/Users/akshayk/Documents/workspace/demo/vast/build/test.c" attributes {dlti.dl_spec = #dlti.dl_spec<>, vast.core.lang = #core<lang c>, vast.core.target_triple = "arm64-apple-macosx15.0.0"} {
    hl.var @var_error, <internal>  sc_static : !hl.ptr<ui32>
    hl.var @var_1, <internal>  sc_static : !hl.ptr<ui32>
    ll.func @func external () -> ui32 {
      %0 = hl.label.decl @basic_0 : !hl.label
      %1 = hl.label.decl @basic_2 : !hl.label
      %2 = hl.label.decl @basic_1 : !hl.label
      %3 = ll.alloca : !hl.ptr<ui32>
      hl.goto %0
      hl.label %1 {
        %5 = hl.const #core.integer<0> : ui32
        ll.store %3, %5 : !hl.ptr<ui32>, ui32
      }
      %4 = ll.load %3 : (!hl.ptr<ui32>) -> ui32
      ll.return %4 : ui32
    }
  }
}