Add .clang-format and run clang-format on runtime/platform.

runtime/platform/utils_linux.h

Index: runtime/platform/utils_linux.h
diff --git a/runtime/platform/utils_linux.h b/runtime/platform/utils_linux.h
index 5be126d8cfc704dfe2a347effd21da78296a860c..b5214fdce3cd3cddb26759fd69274f2fe382f271 100644
--- a/runtime/platform/utils_linux.h
+++ b/runtime/platform/utils_linux.h
@@ -62,8 +62,8 @@ inline uint64_t Utils::HostToLittleEndian64(uint64_t value) {
 
 
 inline char* Utils::StrError(int err, char* buffer, size_t bufsize) {
-#if !defined(__GLIBC__) ||                                              \
-((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE)
+#if !defined(__GLIBC__) ||                                                     \
+    ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE)
   // Use the XSI version.
   if (strerror_r(err, buffer, bufsize) != 0) {
     snprintf(buffer, bufsize, "%s", "strerror_r failed");