[X86] Limit store merge size when implicitfloat is enabled (PR34421)

As suggested by @niravd : https://bugs.llvm.org/show_bug.cgi?id=34421#c2

Differential Revision: https://reviews.llvm.org/D37464

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312534 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed