Misc typos fixes in ./lib folder

Summary: Found via `codespell -q 3 -I ../clang-whitelist.txt -L uint,importd,crasher,gonna,cant,ue,ons,orign,ned`

Reviewers: teemperor

Reviewed By: teemperor

Subscribers: teemperor, jholewinski, jvesely, nhaehnle, whisperity, jfb, cfe-commits

Differential Revision: https://reviews.llvm.org/D55475

llvm-svn: 348755
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 20d6cd6..9fed476 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -2862,7 +2862,7 @@
   case Mips::BI__builtin_mips_precr_sra_ph_w: i = 2; l = 0; u = 31; break;
   case Mips::BI__builtin_mips_precr_sra_r_ph_w: i = 2; l = 0; u = 31; break;
   case Mips::BI__builtin_mips_prepend: i = 2; l = 0; u = 31; break;
-  // MSA instrinsics. Instructions (which the intrinsics maps to) which use the
+  // MSA intrinsics. Instructions (which the intrinsics maps to) which use the
   // df/m field.
   // These intrinsics take an unsigned 3 bit immediate.
   case Mips::BI__builtin_msa_bclri_b: