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

[sivachandra]

Summary

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

[sivachandra]

Increase buffer space at the end of the stack in pthread_create_test

[michaelrj]

LGTM

libc/cmake/modules/LLVMLibCTestRules.cmake

function(add_integration_test test_name)
   target_include_directories(
     ${fq_build_target_name}
     PRIVATE
       ${LIBC_SOURCE_DIR}
       ${LIBC_BUILD_DIR}
       ${LIBC_BUILD_DIR}/include
   )
   target_compile_options(${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
                            -mcpu=${LIBC_GPU_TARGET_ARCHITECTURE}
                            -flto --target=${LIBC_GPU_TARGET_TRIPLE})
   elseif(LIBC_GPU_TARGET_ARCHITECTURE_IS_NVPTX)
     get_nvptx_compile_options(nvptx_options ${LIBC_GPU_TARGET_ARCHITECTURE})
     target_compile_options(${fq_build_target_name} PRIVATE

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

ASSERT_EQ(expec_detached == PTHREAD_CREATE_JOINABLE,
             thread->attrib->detach_state.load() ==
                 static_cast<uint32_t>(__llvm_libc::DetachState::JOINABLE));
   ASSERT_EQ(expec_detached == PTHREAD_CREATE_DETACHED,
             thread->attrib->detach_state.load() ==
                 static_cast<uint32_t>(__llvm_libc::DetachState::DETACHED));
 
   {
     // 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);
 
     for (size_t I = 0; I < test_stacksize; ++I) {
       // Write permissions
       bytes_on_stack[I] = static_cast<uint8_t>(I);
     }