Fix typos in clang

Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:

  archtype
  cas
  classs
  checkk
  compres
  definit
  frome
  iff
  inteval
  ith
  lod
  methode
  nd
  optin
  ot
  pres
  statics
  te
  thru

Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)

Differential revision: https://reviews.llvm.org/D44188

llvm-svn: 329399
diff --git a/clang/www/OpenProjects.html b/clang/www/OpenProjects.html
index ad18909..9d8f4df 100644
--- a/clang/www/OpenProjects.html
+++ b/clang/www/OpenProjects.html
@@ -102,7 +102,7 @@
 
 <li><b>Configuration Manager</b>: Clang/LLVM works on a large number of
 architectures and operating systems and can cross-compile to a similarly large
-number of configurations, but the pitfalls of chosing the command-line
+number of configurations, but the pitfalls of choosing the command-line
 options, making sure the right sub-architecture is chosen and that the correct
 optional elements of your particular system can be a pain.