[profile] Enable on SystemZ.

[• koriakin]

Summary

Depends on D21736, D21737. Once these are in, check-profile passes on SystemZ, so we can enable it.

[vsk]

This lgtm once the dependent patches are in.

As a heads-up: the gcov/SampleProf stuff has lower code coverage on big-endian systems due to xfails in test/tools/llvm-{cov,profdata} and in test/Transforms/SampleProfile. That should really be fixed. But, there's no sense in holding up this patch with that.

Before committing, please also check that building an instrumented stage2 clang on s390x works. I.e:

-DCMAKE_C_COMPILER=ToT/bin/clang -DCMAKE_CXX_COMPILER=ToT/bin/clang++ -DLLVM_PROFILE_DATA_DIR=/tmp -DLLVM_BUILD_INSTRUMENTED=On

compiler-rt/trunk/cmake/config-ix.cmake

 set(ALL_SANITIZER_COMMON_SUPPORTED_ARCH ${X86} ${X86_64} ${PPC64}
     ${ARM32} ${ARM64} ${MIPS32} ${MIPS64} ${S390X})
 set(ALL_ASAN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64}
     ${MIPS32} ${MIPS64} ${PPC64})
 set(ALL_DFSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64})
 set(ALL_LSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64})
 set(ALL_MSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64} ${PPC64})
 set(ALL_PROFILE_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${PPC64}
-    ${MIPS32} ${MIPS64})
+    ${MIPS32} ${MIPS64} ${S390X})
 set(ALL_TSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64} ${PPC64})
 set(ALL_UBSAN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64}
     ${MIPS32} ${MIPS64} ${PPC64} ${S390X})
 set(ALL_SAFESTACK_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM64} ${MIPS32} ${MIPS64})
 set(ALL_CFI_SUPPORTED_ARCH ${X86} ${X86_64} ${MIPS64})
 set(ALL_ESAN_SUPPORTED_ARCH ${X86_64} ${MIPS64})
 set(ALL_SCUDO_SUPPORTED_ARCH ${X86_64})
 set(ALL_XRAY_SUPPORTED_ARCH ${X86_64} ${ARM32} ${ARM64})