Remove unnecessary check for nil in parseExpr

tgo.go

@@ -1120,7 +1120,6 @@ func (c *Compiler) parseCall(frame *Frame, instr *ssa.CallCommon, parentHandle l
 }
 
 func (c *Compiler) parseExpr(frame *Frame, expr ssa.Value) (llvm.Value, error) {
-	if frame != nil {
 	if value, ok := frame.locals[expr]; ok {
 		// Value is a local variable that has already been computed.
 		if value.IsNil() {
@@ -1128,7 +1127,6 @@ func (c *Compiler) parseExpr(frame *Frame, expr ssa.Value) (llvm.Value, error) {
 		}
 		return value, nil
 	}
-	}
 
 	switch expr := expr.(type) {
 	case *ssa.Alloc: