[CMake] Add missing dependency in llvm Support unittests

[steven_wu]

Summary

Casting.cpp in llvm unittests includes "llvm/IR/User.h" which depends on
intrinsic_gen if using module because it needs to build IR module including
Attributes.h.

[dblaikie]

Could you include some details, if you can find them, about which commit introduced this dependency?

[steven_wu]

In D153048#4425950, @dblaikie wrote:

Could you include some details, if you can find them, about which commit introduced this dependency?

I didn't check. I just want to do a quite test on SupportTests and realized it doesn't build anymore. I will do a quick search and make sure to put the context in the commit message.

[steven_wu]

Ah, this is a module specific issue. If you don't have module on, User.h will not pull in Attributes.h so it is fine without intrinsics_gen. Update commit message.

[dblaikie]

In D153048#4426556, @steven_wu wrote:

Ah, this is a module specific issue. If you don't have module on, User.h will not pull in Attributes.h so it is fine without intrinsics_gen. Update commit message.

Cool - thanks!

llvm/unittests/Support/CMakeLists.txt

add_llvm_unittest(SupportTests
   YAMLParserTest.cpp
   buffer_ostream_test.cpp
   formatted_raw_ostream_test.cpp
   raw_fd_stream_test.cpp
   raw_ostream_test.cpp
   raw_pwrite_stream_test.cpp
   raw_sha1_ostream_test.cpp
   xxhashTest.cpp
+
+  DEPENDS
+  intrinsics_gen
   )
 
 target_link_libraries(SupportTests PRIVATE LLVMTestingSupport)
 
 # Disable all warning for AlignOfTest.cpp,
 # as it does things intentionally, and there is no reliable way of
 # disabling all warnings for all the compilers by using pragmas.
 # Don't disable on MSVC, because all incriminated warnings are already disabled