clang-cl: Align help texts for /O1 and O2
clang-cl: Align help texts for /O1 and O2

Makes it a bit easier to see what exactly the difference is.

Also use "same as" instead of "equivalent to", because that's faster to read.

Differential Revision: https://reviews.llvm.org/D56488


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@351061 91177308-0d34-0410-b5e6-96231b3b80d8

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