[FileCheck] - Refactor the code related to string arrays. NFCI.

There are few `std::vector<std::string>` members in
`FileCheckRequest`. This patch changes these arrays to `std::vector<StringRef>`
and refactors the code related to cleanup/improve/simplify it.

Differential revision: https://reviews.llvm.org/D78202

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/utils/FileCheck/FileCheck.cpp b/llvm/utils/FileCheck/FileCheck.cpp
index ef6c62b..3f7d777 100644
--- a/llvm/utils/FileCheck/FileCheck.cpp
+++ b/llvm/utils/FileCheck/FileCheck.cpp
@@ -562,14 +562,14 @@ int main(int argc, char **argv) {
   }
 
   FileCheckRequest Req;
-  for (auto Prefix : CheckPrefixes)
+  for (StringRef Prefix : CheckPrefixes)
     Req.CheckPrefixes.push_back(Prefix);
 
-  for (auto CheckNot : ImplicitCheckNot)
+  for (StringRef CheckNot : ImplicitCheckNot)
     Req.ImplicitCheckNot.push_back(CheckNot);
 
   bool GlobalDefineError = false;
-  for (auto G : GlobalDefines) {
+  for (StringRef G : GlobalDefines) {
     size_t EqIdx = G.find('=');
     if (EqIdx == std::string::npos) {
       errs() << "Missing equal sign in command-line definition '-D" << G