Lack RW-sx metrics, which are missed on mysql integration

[komeda-shinji]

I'm getting values for these six metrics.

• mysql.innodb.s_lock_os_waits
• mysql.innodb.s_lock_spin_waits
• mysql.innodb.s_lock_spin_rounds
• mysql.innodb.x_lock_os_waits
• mysql.innodb.x_lock_spin_waits
• mysql.innodb.x_lock_spin_rounds

However, there are no values for the three metrics for RW-sx spins.

• mysql.innodb.sx_lock_os_waits
• mysql.innodb.sx_lock_spin_waits
• mysql.innodb.sx_lock_spin_rounds

The operation to get the values of these metrics from the result of SHOW ENGINE INNODB STATUS is not implemented in mysql integration.

integrations-core/mysql/datadog_checks/mysql/innodb_metrics.py

Lines 83 to 112 in f5a8b7c

	# SEMAPHORES
	if line.find('Mutex spin waits') == 0:
	# Mutex spin waits 79626940, rounds 157459864, OS waits 698719
	# Mutex spin waits 0, rounds 247280272495, OS waits 316513438
	results['Innodb_mutex_spin_waits'] = long(row[3])
	results['Innodb_mutex_spin_rounds'] = long(row[5])
	results['Innodb_mutex_os_waits'] = long(row[8])
	elif line.find('RW-shared spins') == 0 and line.find(';') > 0:
	# RW-shared spins 3859028, OS waits 2100750; RW-excl spins
	# 4641946, OS waits 1530310
	results['Innodb_s_lock_spin_waits'] = long(row[2])
	results['Innodb_x_lock_spin_waits'] = long(row[8])
	results['Innodb_s_lock_os_waits'] = long(row[5])
	results['Innodb_x_lock_os_waits'] = long(row[11])
	elif line.find('RW-shared spins') == 0 and line.find('; RW-excl spins') == -1:
	# Post 5.5.17 SHOW ENGINE INNODB STATUS syntax
	# RW-shared spins 604733, rounds 8107431, OS waits 241268
	results['Innodb_s_lock_spin_waits'] = long(row[2])
	results['Innodb_s_lock_spin_rounds'] = long(row[4])
	results['Innodb_s_lock_os_waits'] = long(row[7])
	elif line.find('RW-excl spins') == 0:
	# Post 5.5.17 SHOW ENGINE INNODB STATUS syntax
	# RW-excl spins 604733, rounds 8107431, OS waits 241268
	results['Innodb_x_lock_spin_waits'] = long(row[2])
	results['Innodb_x_lock_spin_rounds'] = long(row[4])
	results['Innodb_x_lock_os_waits'] = long(row[7])
	elif line.find('seconds the semaphore:') > 0:
	# --Thread 907205 has waited at handler/ha_innodb.cc line 7156 for 1.00 seconds the semaphore:
	results['Innodb_semaphore_waits'] += 1
	results['Innodb_semaphore_wait_time'] += long(float(row[9])) * 1000