[Parser] Avoid correcting delayed typos in array subscript multiple times.

We correct some typos in `ActOnArraySubscriptExpr` and
`ActOnOMPArraySectionExpr`, so when their result is `ExprError`, we can
end up correcting delayed typos in the same expressions again. In
general it is OK but when `NumTypos` is incorrect, we can hit the
assertion

> Assertion failed: (Entry != DelayedTypos.end() && "Failed to get the state for a TypoExpr!"), function getTypoExprState, file clang/lib/Sema/SemaLookup.cpp, line 5219.

Fix by replacing some subscript `ExprResult` with typo-corrected expressions
instead of keeping the original expressions. Thus if original expressions
contained `TypoExpr`, we'll use corrected expressions instead of trying to
correct them again.

rdar://problem/47403222

Reviewers: rsmith, erik.pilkington, majnemer

Reviewed By: erik.pilkington

Subscribers: jkorous, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D60848

llvm-svn: 359713