runtime: abort when receiving a signal on a non-Go thread on Windows

Currently if a signal lands on a non-Go thread that's handled by the Go
handler, Go will emit a message. However, unlike everywhere else in the
runtime, Go will not abort the process after, and the signal handler
will try to continue executing.

This leads to cascading failures and possibly even memory corruption.

For #45638.

Change-Id: I546f4e82f339d555bed295528d819ac883b92bc6
Reviewed-on: https://go-review.googlesource.com/c/go/+/316809
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/runtime/sys_windows_386.s

@@ -58,7 +58,9 @@ TEXT	runtime·badsignal2(SB),NOSPLIT,$24
 	MOVL	DX, 12(SP)
 	MOVL	$0, 16(SP) // overlapped
 	CALL	*runtime·_WriteFile(SB)
-	MOVL	BP, SI
+
+	// Does not return.
+	CALL	runtime·abort(SB)
 	RET
 
 // faster get/set last error

src/runtime/sys_windows_amd64.s

@@ -96,6 +96,8 @@ TEXT runtime·badsignal2(SB),NOSPLIT|NOFRAME,$48
 	MOVQ	runtime·_WriteFile(SB), AX
 	CALL	AX
 
+	// Does not return.
+	CALL	runtime·abort(SB)
 	RET
 
 // faster get/set last error

src/runtime/sys_windows_arm.s

@@ -97,8 +97,8 @@ TEXT runtime·badsignal2(SB),NOSPLIT|NOFRAME,$0
 	MOVW	runtime·_WriteFile(SB), R12
 	BL	(R12)
 
-	MOVW	R4, R13			// restore SP
+	// Does not return.
-	MOVM.IA.W (R13), [R4, R15]	// pop {r4, pc}
+	B	runtime·abort(SB)
 
 TEXT runtime·getlasterror(SB),NOSPLIT,$0
 	MRC	15, 0, R0, C13, C0, 2

src/runtime/sys_windows_arm64.s

@@ -117,7 +117,9 @@ TEXT runtime·badsignal2(SB),NOSPLIT,$16-0
 	MOVD	runtime·_WriteFile(SB), R12
 	SUB	$16, RSP	// skip over saved frame pointer below RSP
 	BL	(R12)
-	ADD	$16, RSP
+
+	// Does not return.
+	B	runtime·abort(SB)
 
 	RET