compiler: fix basic block context

llvm.AddBasicBlock should never be used. Instead, we should use the
AddBasicBlock method of the current LLVM context.

This didn't lead to any bugs... yet. But probably would, eventually.

compiler/alias.go

@@ -86,7 +86,7 @@ func (b *builder) createAlias(alias llvm.Value) {
  pos := b.program.Fset.Position(b.fn.Pos())
  b.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), b.difunc, llvm.Metadata{})
  }
- entryBlock := llvm.AddBasicBlock(b.llvmFn, "entry")
+ entryBlock := b.ctx.AddBasicBlock(b.llvmFn, "entry")
  b.SetInsertPointAtEnd(entryBlock)
  if b.llvmFn.Type() != alias.Type() {
  b.addError(b.fn.Pos(), "alias function should have the same type as aliasee "+alias.Name())