#### 7.2.4 Features for `dg-add-options`

The supported values of feature for directive `dg-add-options` are:

`arm_neon`
  NEON support. Only ARM targets support this feature, and only then in certain modes; see the arm_neon_ok effective target keyword.
`arm_neon_fp16`
  NEON and half-precision floating point support. Only ARM targets support this feature, and only then in certain modes; see the arm_neon_fp16_ok effective target keyword.
`arm_vfp3`
  arm vfp3 floating point support; see the arm_vfp3_ok effective target keyword.
`bind_pic_locally`
  Add the target-specific flags needed to enable functions to bind locally when using pic/PIC passes in the testsuite.
`c99_runtime`
  Add the target-specific flags needed to access the C99 runtime.
`ieee`
  Add the target-specific flags needed to enable full IEEE compliance mode.
`mips16_attribute`
  `mips16` function attributes. Only MIPS targets support this feature, and only then in certain modes.
`tls`
  Add the target-specific flags needed to use thread-local storage.