[clang] Replacing asserts with static_asserts where appropriate

[eszasip]

Summary

This patch consists of the suggestions of clang-tidy/misc-static-assert check.

[dblaikie]

LGTM, please commit.

[xazax.hun]

Committed in r232367.

lib/Sema/SemaChecking.cpp

ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
   const unsigned NumVals[] = { 1, 0, 1, 1, 1, 2, 2, 3 };
   // where:
   //   C is an appropriate type,
   //   A is volatile _Atomic(C) for __c11 builtins and is C for GNU builtins,
   //   CP is C for __c11 builtins and GNU _n builtins and is C * otherwise,
   //   M is C if C is an integer, and ptrdiff_t if C is a pointer, and
   //   the int parameters are for orderings.
 
-  assert(AtomicExpr::AO__c11_atomic_init == 0 &&
-         AtomicExpr::AO__c11_atomic_fetch_xor + 1 == AtomicExpr::AO__atomic_load
-         && "need to update code for modified C11 atomics");
+  static_assert(AtomicExpr::AO__c11_atomic_init == 0 &&
+                    AtomicExpr::AO__c11_atomic_fetch_xor + 1 ==
+                        AtomicExpr::AO__atomic_load,
+                "need to update code for modified C11 atomics");
   bool IsC11 = Op >= AtomicExpr::AO__c11_atomic_init &&
                Op <= AtomicExpr::AO__c11_atomic_fetch_xor;
   bool IsN = Op == AtomicExpr::AO__atomic_load_n ||
              Op == AtomicExpr::AO__atomic_store_n ||
              Op == AtomicExpr::AO__atomic_exchange_n ||
              Op == AtomicExpr::AO__atomic_compare_exchange_n;
   bool IsAddSub = false;