Apply most suggestions of clang-tidy's performance-unnecessary-value-param

Avoids unnecessary copies. All changes audited & pass tests with asan.
No functional change intended.

llvm-svn: 272190
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index 8aec547..cd7b9a9 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -1664,10 +1664,8 @@
   DEBUG(dbgs() << '\n');
 }
 
-void APInt::divide(const APInt LHS, unsigned lhsWords,
-                   const APInt &RHS, unsigned rhsWords,
-                   APInt *Quotient, APInt *Remainder)
-{
+void APInt::divide(const APInt &LHS, unsigned lhsWords, const APInt &RHS,
+                   unsigned rhsWords, APInt *Quotient, APInt *Remainder) {
   assert(lhsWords >= rhsWords && "Fractional result");
 
   // First, compose the values into an array of 32-bit words instead of
diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
index 54756fb..aed42b2 100644
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -1432,7 +1432,7 @@
 PRINT_OPT_DIFF(char)
 
 void parser<std::string>::printOptionDiff(const Option &O, StringRef V,
-                                          OptionValue<std::string> D,
+                                          const OptionValue<std::string> &D,
                                           size_t GlobalWidth) const {
   printOptionName(O, GlobalWidth);
   outs() << "= " << V;