[llgo] drop debug/DIBuilder.Declare

[axw]

Summary

Companion to D11864, which updates the
DIBuilder bindings to match a recent
change in the underlying API.

We drop the debug/DIBuilder.Declare method
for now, which is unused, as otherwise it will
be broken with the new DIBuilder API in the
Go bindings.

[pcc]

Is this code used at all at the moment? It doesn't look like it is, so maybe we should remove it?

[axw]

Delete unused Declare method

[axw]

In D11891#225503, @pcc wrote:

Is this code used at all at the moment? It doesn't look like it is, so maybe we should remove it?

Yes, done. I'll resurrect it if/when we need it.

[axw]

@pcc Seeing as you suggested the alternative change, I'll assume this is good to land.

[axw]

Rebase

[pcc]

LGTM

debug/debug.go

 
 // PopFunction pops the previously pushed function off the scope stack.
 func (d *DIBuilder) PopFunction() {
   d.lb = llvm.Metadata{}
   d.fn = llvm.Metadata{}
   d.fnFile = ""
 }
 
-// Declare creates an llvm.dbg.declare call for the specified function
-// parameter or local variable.
-func (d *DIBuilder) Declare(b llvm.Builder, v ssa.Value, llv llvm.Value, paramIndex int) {
-  tag := tagAutoVariable
-  if paramIndex >= 0 {
-    tag = tagArgVariable
-  }
-  var diFile llvm.Metadata
-  var line int
-  if file := d.fset.File(v.Pos()); file != nil {
-    line = file.Line(v.Pos())
-    diFile = d.getFile(file)
-  }
-  localVar := d.builder.CreateLocalVariable(d.scope(), llvm.DILocalVariable{
-    Tag:   tag,
-    Name:  llv.Name(),
-    File:  diFile,
-    Line:  line,
-    ArgNo: paramIndex + 1,
-    Type:  d.DIType(v.Type()),
-  })
-  expr := d.builder.CreateExpression(nil)
-  d.builder.InsertDeclareAtEnd(llv, localVar, expr, b.GetInsertBlock())
-}
-
 // Value creates an llvm.dbg.value call for the specified register value.
 func (d *DIBuilder) Value(b llvm.Builder, v ssa.Value, llv llvm.Value, paramIndex int) {
   // TODO(axw)
 }
 
 // SetLocation sets the current debug location.
 func (d *DIBuilder) SetLocation(b llvm.Builder, pos token.Pos) {
   if !pos.IsValid() {