Add Support to llvm-c-test dependancies

[deadalnix]

Summary

As per title. It is required and don't get linked in in some builds.

[mehdi_amini]

This should solve the build failure with BUILD_SHARED_LIBS=ON (hopefully), but it is not clear *why* it is needed in this case?

[mehdi_amini]

Please go ahead, you pulled some ADT directly in llvm-c-test which requires a direct dependency.
This is covered with static build because cmake will pulled transitive dependency, but not on build with shared libraries for individual components.

tools/llvm-c-test/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   ${LLVM_TARGETS_TO_BUILD}
   BitReader
   Core
   MCDisassembler
   Object
+  Support
   Target
   )
 
 # We should only have llvm-c-test use libLLVM if libLLVM is built with the
 # default list of components. Using libLLVM with custom components can result in
 # build failures.
 
 set (USE_LLVM_DYLIB FALSE)