Use braced initialization

I didn't apply braced initialization to very common C programming
patterns in the unittest because when something is extremely common, I
think it increases cognitive load when reading. For example
  int fd = open(...);
vs
  int fd{open(...)};

I did change all uses in the runtime implementation as requested in code
review.

Author: tblah

flang/runtime/extensions.cpp

@@ -143,13 +143,13 @@ void RTNAME(Sleep)(std::int64_t seconds) {
 #ifndef _WIN32
 std::int64_t FORTRAN_PROCEDURE_NAME(access)(const char *name,
     std::int64_t nameLength, const char *mode, std::int64_t modeLength) {
-  std::int64_t ret = -1;
+  std::int64_t ret{-1};
   if (nameLength <= 0 || modeLength <= 0 || !name || !mode) {
     return ret;
   }
 
   // ensure name is null terminated
-  char *newName = nullptr;
+  char *newName{nullptr};
   if (name[nameLength - 1] != '\0') {
     newName = static_cast<char *>(std::malloc(nameLength + 1));
     std::memcpy(newName, name, nameLength);
@@ -158,11 +158,11 @@ std::int64_t FORTRAN_PROCEDURE_NAME(access)(const char *name,
   }
 
   // calculate mode
-  bool read = false;
-  bool write = false;
-  bool execute = false;
-  bool exists = false;
-  int imode = 0;
+  bool read{false};
+  bool write{false};
+  bool execute{false};
+  bool exists{false};
+  int imode{0};
 
   for (std::int64_t i = 0; i < modeLength; ++i) {
     switch (mode[i]) {

flang/unittests/Runtime/AccessTest.cpp

@@ -24,10 +24,10 @@ namespace {
 struct AccessTests : public CrashHandlerFixture {};
 
 struct AccessType {
-  bool read = false;
-  bool write = false;
-  bool execute = false;
-  bool exists = false;
+  bool read{false};
+  bool write{false};
+  bool execute{false};
+  bool exists{false};
 };
 
 } // namespace
@@ -44,15 +44,15 @@ static std::string addPIDSuffix(const char *name) {
 
 static std::filesystem::path createTemporaryFile(
     const char *name, const AccessType &accessType) {
-  std::filesystem::path path =
-      std::filesystem::temp_directory_path() / addPIDSuffix(name);
+  std::filesystem::path path{
+      std::filesystem::temp_directory_path() / addPIDSuffix(name)};
 
   // O_CREAT | O_EXCL enforces that this file is newly created by this call.
   // This feels risky. If we don't have permission to create files in the
   // temporary directory or if the files already exist, the test will fail.
   // But we can't use std::tmpfile() because we need a path to the file and
   // to control the filesystem permissions
-  mode_t mode = 0;
+  mode_t mode{0};
   if (accessType.read) {
     mode |= S_IRUSR;
   }
@@ -75,7 +75,7 @@ static std::filesystem::path createTemporaryFile(
 
 static std::int64_t callAccess(
     const std::filesystem::path &path, const AccessType &accessType) {
-  const char *cpath = path.c_str();
+  const char *cpath{path.c_str()};
   std::int64_t pathlen = std::strlen(cpath);
 
   std::string mode;