case *ast.SendStmt:
		f.walk(&n.Chan, ctxExpr, visit)
		f.walk(&n.Value, ctxExpr, visit)
	case *ast.IncDecStmt:
		f.walk(&n.X, ctxExpr, visit)
	case *ast.AssignStmt:
		f.walk(n.Lhs, ctxExpr, visit)
		if len(n.Lhs) == 2 && len(n.Rhs) == 1 {
			f.walk(n.Rhs, ctxAssign2, visit)
		} else {
			f.walk(n.Rhs, ctxExpr, visit)
		}
	case *ast.GoStmt:
		f.walk(n.Call, ctxExpr, visit)
	case *ast.DeferStmt:

pkg go/types, type Info struct, Types map[ast.Expr]TypeAndValue
pkg go/types, type Info struct, Uses map[*ast.Ident]Object
pkg go/types, type Initializer struct
pkg go/types, type Initializer struct, Lhs []*Var
pkg go/types, type Initializer struct, Rhs ast.Expr
pkg go/types, type Interface struct
pkg go/types, type Label struct
pkg go/types, type Map struct
pkg go/types, type MethodSet struct

pkg go/ast, type ArrayType struct, Elt Expr
pkg go/ast, type ArrayType struct, Lbrack token.Pos
pkg go/ast, type ArrayType struct, Len Expr
pkg go/ast, type AssignStmt struct
pkg go/ast, type AssignStmt struct, Lhs []Expr
pkg go/ast, type AssignStmt struct, Rhs []Expr
pkg go/ast, type AssignStmt struct, Tok token.Token
pkg go/ast, type AssignStmt struct, TokPos token.Pos
pkg go/ast, type BadDecl struct

				p.errorf("expected simple register reference")
			}
			a.Type = obj.TYPE_REG
			a.Reg = r1
			if r2 != 0 {
				// Form is R1:R2. It is on RHS and the second register
				// needs to go into the LHS.
				panic("cannot happen (Addr.Reg2)")
			}
		}
		// fmt.Printf("REG %s\n", obj.Dconv(&emptyProg, 0, a))
		p.expectOperandEnd()
		return
	}

	// Constant.
	haveConstant := false

<p>
Type inference solves type equations through <i>type unification</i>.
Type unification recursively compares the LHS and RHS types of an
equation, where either or both types may be or contain bound type parameters,
and looks for type arguments for those type parameters such that the LHS
and RHS match (become identical or assignment-compatible, depending on
context).