$ GO_GCFLAGS='-l=4' ./make.bash
...

$ go version
go version devel +cfb0d34992 Sun Feb 19 17:16:01 2017 +0000 linux/amd64

$ cd cmd/objdump
$ go test -v                                                
=== RUN   TestDisasm 
--- FAIL: TestDisasm (0.13s)
	objdump_test.go:156: disassembly missing 'CALL fmt.Println(SB)'
	objdump_test.go:156: full disassembly:
		TEXT main.main(SB) /home/david/go/src/cmd/objdump/testdata/fmthello.go
			fmthello.go:5	0x486d20	64488b0c25f8ffffff	FS MOVQ FS:0xfffffff8, CX		
			fmthello.go:5	0x486d29	483b6110		CMPQ 0x10(CX), SP			
			fmthello.go:5	0x486d2d	767a			JBE 0x486da9				
			fmthello.go:5	0x486d2f	4883ec58		SUBQ $0x58, SP				
			fmthello.go:5	0x486d33	48896c2450		MOVQ BP, 0x50(SP)			
			fmthello.go:5	0x486d38	488d6c2450		LEAQ 0x50(SP), BP			
			fmthello.go:6	0x486d3d	48c744244000000000	MOVQ $0x0, 0x40(SP)			
			fmthello.go:6	0x486d46	48c744244800000000	MOVQ $0x0, 0x48(SP)			
			fmthello.go:6	0x486d4f	488d05aae20000		LEAQ 0xe2aa(IP), AX			
			fmthello.go:6	0x486d56	4889442440		MOVQ AX, 0x40(SP)			
			fmthello.go:6	0x486d5b	488d05ae3e0300		LEAQ 0x33eae(IP), AX			
			fmthello.go:6	0x486d62	4889442448		MOVQ AX, 0x48(SP)			
			fmthello.go:6	0x486d67	488b05f2a50700		MOVQ 0x7a5f2(IP), AX			
			fmthello.go:6	0x486d6e	488d0d2b640700		LEAQ 0x7642b(IP), CX			
			fmthello.go:6	0x486d75	48890c24		MOVQ CX, 0(SP)				
			fmthello.go:6	0x486d79	4889442408		MOVQ AX, 0x8(SP)			
			fmthello.go:6	0x486d7e	488d442440		LEAQ 0x40(SP), AX			
			fmthello.go:6	0x486d83	4889442410		MOVQ AX, 0x10(SP)			
			fmthello.go:6	0x486d88	48c744241801000000	MOVQ $0x1, 0x18(SP)			
			fmthello.go:6	0x486d91	48c744242001000000	MOVQ $0x1, 0x20(SP)			
			fmthello.go:6	0x486d9a	e80170ffff		CALL fmt.Fprintln(SB)			
			fmthello.go:7	0x486d9f	488b6c2450		MOVQ 0x50(SP), BP			
			fmthello.go:7	0x486da4	4883c458		ADDQ $0x58, SP				
			fmthello.go:7	0x486da8	c3			RET					
			fmthello.go:5	0x486da9	e8a29ffcff		CALL runtime.morestack_noctxt(SB)	
			fmthello.go:5	0x486dae	e96dffffff		JMP main.main(SB)			
=== RUN   TestDisasmExtld
--- FAIL: TestDisasmExtld (0.18s)
	objdump_test.go:181: disassembly missing 'CALL fmt.Println(SB)'
	objdump_test.go:181: full disassembly:
		TEXT main.main(SB) /home/david/go/src/cmd/objdump/testdata/fmthello.go
			fmthello.go:5	0x4872a0	64488b0c25f8ffffff	FS MOVQ FS:0xfffffff8, CX		
			fmthello.go:5	0x4872a9	483b6110		CMPQ 0x10(CX), SP			
			fmthello.go:5	0x4872ad	767a			JBE 0x487329				
			fmthello.go:5	0x4872af	4883ec58		SUBQ $0x58, SP				
			fmthello.go:5	0x4872b3	48896c2450		MOVQ BP, 0x50(SP)			
			fmthello.go:5	0x4872b8	488d6c2450		LEAQ 0x50(SP), BP			
			fmthello.go:6	0x4872bd	48c744244000000000	MOVQ $0x0, 0x40(SP)			
			fmthello.go:6	0x4872c6	48c744244800000000	MOVQ $0x0, 0x48(SP)			
			fmthello.go:6	0x4872cf	488d054ae90000		LEAQ 0xe94a(IP), AX			
			fmthello.go:6	0x4872d6	4889442440		MOVQ AX, 0x40(SP)			
			fmthello.go:6	0x4872db	488d056e450300		LEAQ 0x3456e(IP), AX			
			fmthello.go:6	0x4872e2	4889442448		MOVQ AX, 0x48(SP)			
			fmthello.go:6	0x4872e7	488b05c2c12700		MOVQ 0x27c1c2(IP), AX			
			fmthello.go:6	0x4872ee	488d0d0b9d2700		LEAQ 0x279d0b(IP), CX			
			fmthello.go:6	0x4872f5	48890c24		MOVQ CX, 0(SP)				
			fmthello.go:6	0x4872f9	4889442408		MOVQ AX, 0x8(SP)			
			fmthello.go:6	0x4872fe	488d442440		LEAQ 0x40(SP), AX			
			fmthello.go:6	0x487303	4889442410		MOVQ AX, 0x10(SP)			
			fmthello.go:6	0x487308	48c744241801000000	MOVQ $0x1, 0x18(SP)			
			fmthello.go:6	0x487311	48c744242001000000	MOVQ $0x1, 0x20(SP)			
			fmthello.go:6	0x48731a	e80170ffff		CALL fmt.Fprintln(SB)			
			fmthello.go:7	0x48731f	488b6c2450		MOVQ 0x50(SP), BP			
			fmthello.go:7	0x487324	4883c458		ADDQ $0x58, SP				
			fmthello.go:7	0x487328	c3			RET					
			fmthello.go:5	0x487329	e8329ffcff		CALL runtime.morestack_noctxt(SB)	
			fmthello.go:5	0x48732e	e96dffffff		JMP main.main(SB)			
FAIL
exit status 1
FAIL	cmd/objdump	0.564s