[NFC] Fix misspellings of effects (#87795)

clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp

@@ -30,7 +30,7 @@
 // was not consciously intended, and therefore it might have been unreachable.
 //
 // This checker uses eval::Call for modeling pure functions (functions without
-// side effets), for which their `Summary' is a precise model. This avoids
+// side effects), for which their `Summary' is a precise model. This avoids
 // unnecessary invalidation passes. Conflicts with other checkers are unlikely
 // because if the function has no other effects, other checkers would probably
 // never want to improve upon the modeling done by this checker.

llvm/lib/Transforms/Scalar/NewGVN.cpp

@@ -4019,7 +4019,7 @@ bool NewGVN::eliminateInstructions(Function &F) {
           // dominated defs as dead.
           if (Def) {
             // For anything in this case, what and how we value number
-            // guarantees that any side-effets that would have occurred (ie
+            // guarantees that any side-effects that would have occurred (ie
             // throwing, etc) can be proven to either still occur (because it's
             // dominated by something that has the same side-effects), or never
             // occur.  Otherwise, we would not have been able to prove it value