Align all scalar numbers to LLVM_YAML_IS_FLOW_SEQUENCE_VECTOR

Otherwise, yamlize in YAMLTraits.h might be wrongly defined.
This makes some AMDGPU tests fail when LLVM_LINK_LLVM_DYLIB is set.

Differential Revision: https://reviews.llvm.org/D30508

llvm-svn: 299415