[libc] Add -fno-exceptions and -fno-rtti to integration test build.

Also adjust pthread_create_test to accomodate large page sizes. Both
these changes should now fix the full build builders.

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D151158

Author: Siva Chandra Reddy

libc/cmake/modules/LLVMLibCTestRules.cmake

@@ -513,7 +513,7 @@ function(add_integration_test test_name)
       ${LIBC_BUILD_DIR}/include
   )
   target_compile_options(${fq_build_target_name}
-                         PRIVATE -fpie -ffreestanding ${INTEGRATION_TEST_COMPILE_OPTIONS})
+      PRIVATE -fpie -ffreestanding -fno-exceptions -fno-rtti ${INTEGRATION_TEST_COMPILE_OPTIONS})
   # The GPU build requires overriding the default CMake triple and architecture.
   if(LIBC_GPU_TARGET_ARCHITECTURE_IS_AMDGPU)
     target_compile_options(${fq_build_target_name} PRIVATE

libc/test/integration/src/pthread/pthread_create_test.cpp

@@ -103,10 +103,8 @@ static void *successThread(void *Arg) {
 
   {
     // Allocate some bytes on the stack on most of the stack and make sure we
-    // have read/write permissions on the memory. -EXEC_PAGESIZE / 2 just as a
-    // buffer so we don't go beyond our limits (no nested function calls / not
-    // much other data on the stack so should be enough).
-    size_t test_stacksize = expec_stacksize - EXEC_PAGESIZE / 2;
+    // have read/write permissions on the memory.
+    size_t test_stacksize = expec_stacksize - 1024;
     volatile uint8_t *bytes_on_stack =
         (volatile uint8_t *)__builtin_alloca(test_stacksize);