Skip libclang_rt build check during non-build stages

[emaste]

Summary

Non-build stages (such as cleandir) do not determine COMPILER_TYPE and set it to "none". Do not produce an error in this case.

Also, remove the quotes on the error string. They are unnecessary (and were printed as part of the error string).

This partially fixes the WITH_ASAN / WITH_UBSAN build.

Sponsored by: The FreeBSD Foundation

[emaste]

WITH_ASAN build still fails with this odd error (https://cirrus-ci.com/task/6720990509006848?logs=main#L2051):

--- all_subdir_lib/clang ---
Included from /tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/OpenMP/OMP.td:13:
--- llvm/Frontend/OpenMP/OMP.h.inc ---
Included from /tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/OpenMP/OMP.td:13:
/tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/Directive/DirectiveBase.td:38:38: error: Variable not defined: 'false'
  bit makeEnumAvailableInNamespace = false;
                                     ^
Included from /tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/OpenMP/OMP.td:13:
/tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/Directive/DirectiveBase.td:41:38: error: Variable not defined: 'false'
  bit enableBitmaskEnumInNamespace = false;
                                     ^
Included from /tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/OpenMP/OMP.td:13:
/tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/Directive/DirectiveBase.td:66:19: error: Variable not defined: 'false'
  bit isDefault = false;
                  ^
--- llvm/Frontend/OpenMP/OMP.inc ---
/tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/Directive/DirectiveBase.td:38:38: error: Variable not defined: 'false'
  bit makeEnumAvailableInNamespace = false;
                                     ^
Included from /tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/OpenMP/OMP.td:13:
/tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/Directive/DirectiveBase.td:41:38: error: Variable not defined: 'false'
  bit enableBitmaskEnumInNamespace = false;
                                     ^
Included from /tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/OpenMP/OMP.td:13:
/tmp/cirrus-ci-build/contrib/llvm-project/llvm/include/llvm/Frontend/Directive/DirectiveBase.td:66:19: error: Variable not defined: 'false'
  bit isDefault = false;
                  ^
...

but the build makes it much further

[emaste]

rebase
PR: 260099

[dim]

Yeah this seems right to me. :)