You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: blockopt.go
    path of file: ./repos/goreporter/vendor/golang.org/x/tools/go/ssa
    
    the code of the file until where you have to start completion: // Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package ssa

// Simple block optimizations to simplify the control flow graph.

// TODO(adonovan): opt: instead of creating several "unreachable" blocks
// per function in the Builder, reuse a single one (e.g. at Blocks[1])
// to reduce garbage.

import (
	"fmt"
	"os"
)

// If true, perform sanity checking and show progress at each
// successive iteration of optimizeBlocks.  Very verbose.
const debugBlockOpt = false

// markReachable sets Index=-1 for all blocks reachable from b.
func markReachable(b *BasicBlock) {
	b.Index = -1
	for _, succ := range b.Succs {
		if succ.Index == 0 {
			markReachable(succ)
		}
	}
}

// 
    
func fuseBlocks(f *Function, a *BasicBlock) bool {
	if len(a.Succs) != 1 {
		return false
	}
	b := a.Succs[0]
	if len(b.Preds) != 1 {
		return false
	}

	// Degenerate &&/|| ops may result in a straight-line CFG
	// containing Ï†-nodes. (Ideally we'd replace such them with
	// their sole operand but that requires Referrers, built later.)
	if b.hasPhi() {
		return false // not sound without further effort
	}

	// Eliminate jump at end of A, then copy all of B across.
	a.Instrs = append(a.Instrs[:len(a.Instrs)-1], b.Instrs...)
	for _, instr := range b.Instrs {
		instr.setBlock(a)
	}

	// A inherits B's successors
	a.Succs = append(a.succs2[:0], b.Succs...)

	// Fix up Preds links of all successors of B.
	for _, c := range b.Succs {
		c.replacePred(b, a)
	}

	if debugBlockOpt {
		fmt.Fprintln(os.Stderr, "fuseBlocks", a, b)
	}

	f.Blocks[b.Index] = nil // delete b
	return true
}