There are instances where using paired vector stores leads to significant
performance degradation due to issues with store forwarding.To avoid falling
into this trap with compiler - generated code, we will not emit these
instructions unless the user requests them explicitly(with a builtin or by
specifying the option).
Reviewed By : lei, amyk, saghir
Differential Revision: https://reviews.llvm.org/D127218
e09f6ff3c1