The recent suffix-log-path_test.c checks for a full stacktrace and
since on some arm-linux-gnu configuration the slow unwinder is used
on default (when the compiler emits thumb code as default), it
requires -funwind-tables on tests.
It also seems to fix the issues disable by d025df3c1de.
Testing for Linux using NOT ANDROID AND NOT WINDOWS AND NOT APPLE will break if more operating systems are added in future, and it's not obvious to me that this list is complete now. This is tested with if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux") elsewhere in compiler-rt, which looks like a better way to do this.