test: 修复llvm升级导致tdd用例部分失败问题

方案描述：
1、llvm升级之后对while(1)死循环和给空指针赋值的场景有错误优化的情况；
   用例中在相关函数之前添加__attribute__((optnone))禁止编译器进行错误优化。

Close：#I6V2LN

Signed-off-by: zhangdengyu <zhangdengyu2@huawei.com>
Change-Id: Ic7150909c12a599aeeb0a55b983dfad7a0631cdc

testsuites/unittest/basic/exc/smoke/it_test_exc_001.cpp

@@ -30,7 +30,7 @@
  */
 #include "it_test_exc.h"
 
-static int TestCase(void)
+__attribute__((optnone)) static int TestCase(void)
 {
     int ret;
     int status = 0;

testsuites/unittest/basic/exc/smoke/it_test_exc_002.cpp

@@ -31,7 +31,7 @@
 #include "it_test_exc.h"
 #include "pthread.h"
 
-static void *ThreadFunc2(void *arg)
+__attribute__((optnone)) static void *ThreadFunc2(void *arg)
 {
     while (1) {
     }
@@ -39,7 +39,7 @@ static void *ThreadFunc2(void *arg)
     return nullptr;
 }
 
-static void *ThreadFunc1(void *arg)
+__attribute__((optnone)) static void *ThreadFunc1(void *arg)
 {
     int *test = nullptr;
     *test = 0x1;
@@ -77,7 +77,8 @@ static int TestThread(void)
     return 0;
 }
 
-static int TestCase(void)
+
+__attribute__((optnone)) static int TestCase(void)
 {
     int *test = nullptr;
     int count = 5;

testsuites/unittest/basic/exc/smoke/it_test_exc_003.cpp

@@ -34,14 +34,15 @@
 #define TEST_THREAD_COUNT 5
 static volatile int g_testCondFlag;
 static int g_count[TEST_THREAD_COUNT];
-static void *ThreadFunc2(void *arg)
+
+__attribute__((optnone)) static void *ThreadFunc2(void *arg)
 {
     int count = *(int *)arg;
     int *test = nullptr;
 
     g_testCondFlag++;
 
-    while (g_testCondFlag < 2) {
+    while (g_testCondFlag < 2) { /* 2, no special meaning  */
     }
 
     *test = 0x1;
@@ -83,7 +84,7 @@ static int TestThread(void)
     return 0;
 }
 
-static int TestCase(void)
+__attribute__((optnone)) static int TestCase(void)
 {
     int *test = nullptr;
     int count = 5;

testsuites/unittest/basic/exc/smoke/it_test_exc_004.cpp

@@ -33,7 +33,7 @@
 
 #define TEST_THREAD_COUNT 5
 
-static int TestThread(void)
+__attribute__((optnone)) static int TestThread(void)
 {
     int ret;
     int *test = nullptr; // For triggering an exceptioin
@@ -53,7 +53,7 @@ static int TestThread(void)
     return 0;
 }
 
-static int TestCase(void)
+__attribute__((optnone)) static int TestCase(void)
 {
     int count = 5;
     int status = 0;

testsuites/unittest/basic/exc/smoke/it_test_exc_005.cpp

@@ -30,7 +30,7 @@
  */
 #include "it_test_exc.h"
 
-static void Child(void)
+__attribute__((optnone)) static void Child(void)
 {
     while (1) {
         printf("@@@@@@@@@@@@@ pid : %d getppid : %d @@@@@@@@@@@@@@@@\n", getpid(), getppid());
@@ -41,7 +41,7 @@ static void TestKill(int sig)
     exit(0);
 }
 
-static int TestCase(void)
+__attribute__((optnone)) static int TestCase(void)
 {
     int ret;
     void (*retptr)(int) = NULL;