[Darwin, testsuite, committed] Fix framework-1.c on later Darwin.
The test works by checking that a known framework path is accessible
when the '-F' option is given. We need to find a framework path that
exists across a range of Darwin versions, and parseable by GCC. This
adjusts the test to use a header path that exists and is parsable from
Darwin9 through Darwin19.
tested with Darwin9 through Darwin19 SDKs on x86-64-darwin16,
applied to mainline,