go/analysis/passes/asmdecl: Correct identify writeResult instructions

This CL ensure all occurrences of writeResult instructions are identified,
not just those at the beginning of the line without indentation.

This CL also fixes this and changed testcases to match other ABIInternal
test.

Change-Id: I1ce6ea22a227902819dc4e0caafa4bace79c15fe
Reviewed-on: https://go-review.googlesource.com/c/tools/+/620056
Reviewed-by: Cherry Mui <[email protected]>
Reviewed-by: Carlos Amedee <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: mengzhuo

go/analysis/passes/asmdecl/asmdecl.go

@@ -354,7 +354,7 @@ Files:
 
 			if abi == "ABIInternal" && !haveRetArg {
 				for _, ins := range archDef.writeResult {
-					if strings.HasPrefix(line, ins) {
+					if strings.Contains(line, ins) {
 						haveRetArg = true
 						break
 					}

go/analysis/passes/asmdecl/testdata/src/a/asm.go

@@ -30,7 +30,6 @@ func returnint() int
 func returnbyte(x int) byte
 func returnnamed(x byte) (r1 int, r2 int16, r3 string, r4 byte)
 func returnintmissing() int
-func returnsyscall()
 func leaf(x, y int) int
 
 func noprof(x int)
@@ -55,5 +54,6 @@ func pickFutureABI(x int)
 
 func returnABIInternal() int
 func returnmissingABIInternal() int
+func returnsyscallABIInternal() int
 
 func retjmp() int

go/analysis/passes/asmdecl/testdata/src/a/asm1.s

@@ -354,7 +354,7 @@ TEXT ·returnmissingABIInternal<ABIInternal>(SB), NOSPLIT, $32
 	RET // want `RET without writing to result register`
 
 // issue 69352
-TEXT ·returnsyscall<ABIInternal>(SB),0,$0-0
+TEXT ·returnsyscallABIInternal<ABIInternal>(SB), NOSPLIT, $0
 	MOVQ	$123, CX
 	SYSCALL
 	RET

go/analysis/passes/asmdecl/testdata/src/a/asm11.s

@@ -13,7 +13,7 @@ TEXT ·returnmissingABIInternal<ABIInternal>(SB), NOSPLIT, $8
 	RET // want `RET without writing to result register`
 
 // issue 69352
-TEXT ·returnsyscall<ABIInternal>(SB),0,$0-0
+TEXT ·returnsyscallABIInternal<ABIInternal>(SB), NOSPLIT, $0
 	MOV	$123, X20
 	ECALL
 	RET

go/analysis/passes/asmdecl/testdata/src/a/asm7.s

@@ -200,7 +200,7 @@ TEXT ·returnmissingABIInternal<ABIInternal>(SB), NOSPLIT, $8
 	RET // want `RET without writing to result register`
 
 // issue 69352
-TEXT ·returnsyscall<ABIInternal>(SB),0,$0-0
+TEXT ·returnsyscallABIInternal<ABIInternal>(SB), NOSPLIT, $0
 	MOVD	$123, R10
 	SYSCALL
 	RET