Disable GCC optimizations for builtin functions in lldb tests

This patch adds new default flag -fno-builtin which forces gcc to not optimize builtin functions.
For example, without this flag GCC replaces printf("hello\n") -> puts("hello") even if -O0 was specified

Also this patch fixes the MiDataTestCase.test_lldbmi_data_disassemble test on Linux/gcc.

llvm-svn: 237118