[Modules] Add 'gnuinlineasm' to the 'requires-declaration' feature-list.

This adds support for modules that require (no-)gnu-inline-asm
environment, such as the compiler builtin cpuid submodule.

This is the gnu-inline-asm variant of https://reviews.llvm.org/D23871

Differential Revision: https://reviews.llvm.org/D23905

rdar://problem/26931199

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@280159 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit b69026bf2c3fabafe17600662c9824aed7ce7b5c)
7 files changed