Fixed failures from changing values of thread_stack and thread_cache_size

Added --thread_cache_size=0 to slow_launch_time_func.test as otherwise
the new thread would start too fast to be counted as a slow_launch_thread.

mysql-test/suite/sys_vars/r/sysvars_server_notembedded.result

@@ -4533,12 +4533,12 @@ READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	REQUIRED
 VARIABLE_NAME	THREAD_CACHE_SIZE
 SESSION_VALUE	NULL
-GLOBAL_VALUE	0
-GLOBAL_VALUE_ORIGIN	COMPILE-TIME
-DEFAULT_VALUE	0
+GLOBAL_VALUE	151
+GLOBAL_VALUE_ORIGIN	AUTO
+DEFAULT_VALUE	256
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	BIGINT UNSIGNED
-VARIABLE_COMMENT	How many threads we should keep in a cache for reuse
+VARIABLE_COMMENT	How many threads we should keep in a cache for reuse. These are freed after 5 minutes of idle time
 NUMERIC_MIN_VALUE	0
 NUMERIC_MAX_VALUE	16384
 NUMERIC_BLOCK_SIZE	1
@@ -4645,9 +4645,9 @@ READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	REQUIRED
 VARIABLE_NAME	THREAD_STACK
 SESSION_VALUE	NULL
-GLOBAL_VALUE	295936
+GLOBAL_VALUE	296960
 GLOBAL_VALUE_ORIGIN	COMPILE-TIME
-DEFAULT_VALUE	295936
+DEFAULT_VALUE	296960
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	BIGINT UNSIGNED
 VARIABLE_COMMENT	The stack size for each thread

mysql-test/suite/sys_vars/r/thread_stack_basic.result

 select @@global.thread_stack;
 @@global.thread_stack
-295936
+296960
 select @@session.thread_stack;
 ERROR HY000: Variable 'thread_stack' is a GLOBAL variable
 show global variables like 'thread_stack';
 Variable_name	Value
-thread_stack	295936
+thread_stack	296960
 show session variables like 'thread_stack';
 Variable_name	Value
-thread_stack	295936
+thread_stack	296960
 select * from information_schema.global_variables where variable_name='thread_stack';
 VARIABLE_NAME	VARIABLE_VALUE
-THREAD_STACK	295936
+THREAD_STACK	296960
 select * from information_schema.session_variables where variable_name='thread_stack';
 VARIABLE_NAME	VARIABLE_VALUE
-THREAD_STACK	295936
+THREAD_STACK	296960
 set global thread_stack=1;
 ERROR HY000: Variable 'thread_stack' is a read only variable
 set session thread_stack=1;

mysql-test/suite/sys_vars/t/slow_launch_time_func-master.opt

+--thread_cache_size=0