tests/kernel: Bump stack sizes for a few tests on qemu_x86

These tests had very small stacks, and the rbtree scheduler on
qemu_x86 (which does need a little extra stack room, though not much)
is bumping up against the limit.  Increase by ~128 bytes in most
cases.  In the case of the mbox_api test, there are other platforms
(which don't use the tree) which are right against the limit already
and will fail to link with a larger stack, so bump it for qemu_x86
only.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>

tests/kernel/mbox/mbox_api/src/test_mbox_api.c

@@ -7,7 +7,11 @@
 #include <ztest.h>
 
 #define TIMEOUT 100
+#if !defined(CONFIG_BOARD_QEMU_X86)
 #define STACK_SIZE (512 + CONFIG_TEST_EXTRA_STACKSIZE)
+#else
+#define STACK_SIZE (640 + CONFIG_TEST_EXTRA_STACKSIZE)
+#endif
 #define MAIL_LEN 64
 
 /**TESTPOINT: init via K_MBOX_DEFINE*/

tests/kernel/sleep/src/main.c

@@ -24,9 +24,9 @@
 #include <stdbool.h>
 
 #if defined(CONFIG_ASSERT) && defined(CONFIG_DEBUG)
-#define THREAD_STACK    (384 + CONFIG_TEST_EXTRA_STACKSIZE)
+#define THREAD_STACK    (512 + CONFIG_TEST_EXTRA_STACKSIZE)
 #else
-#define THREAD_STACK    (256 + CONFIG_TEST_EXTRA_STACKSIZE)
+#define THREAD_STACK    (384 + CONFIG_TEST_EXTRA_STACKSIZE)
 #endif
 
 #define TEST_THREAD_PRIORITY	-4

tests/kernel/threads/lifecycle/lifecycle_api/src/test_threads_set_priority.c

@@ -6,7 +6,7 @@
 
 #include <ztest.h>
 
-#define STACK_SIZE (256 + CONFIG_TEST_EXTRA_STACKSIZE)
+#define STACK_SIZE (384 + CONFIG_TEST_EXTRA_STACKSIZE)
 K_THREAD_STACK_EXTERN(tstack);
 extern struct k_thread tdata;
 static int thread2_data;

tests/kernel/threads/scheduling/schedule_api/src/test_sched.h

@@ -10,7 +10,7 @@
 #include <zephyr.h>
 #include <ztest.h>
 
-#if defined(CONFIG_RISCV32)
+#if defined(CONFIG_RISCV32) || defined(CONFIG_X86)
 #define STACK_SIZE 512
 #else
 #define STACK_SIZE (256 + CONFIG_TEST_EXTRA_STACKSIZE)