Bug 1924278 - Remove whitespace in literal operator declarations. r=nika

That form has been deprecated, and clang trunk now complains about it.
See https://cplusplus.github.io/CWG/issues/2521.html

Differential Revision: https://phabricator.services.mozilla.com/D225560

mfbt/Literals.h

@@ -16,19 +16,19 @@
 //
 // size_t page_size = 4_KiB;
 //
-constexpr size_t operator"" _KiB(unsigned long long int aNum) {
+constexpr size_t operator""_KiB(unsigned long long int aNum) {
   return size_t(aNum) * 1024;
 }
 
-constexpr size_t operator"" _KiB(long double aNum) {
+constexpr size_t operator""_KiB(long double aNum) {
   return size_t(aNum * 1024);
 }
 
-constexpr size_t operator"" _MiB(unsigned long long int aNum) {
+constexpr size_t operator""_MiB(unsigned long long int aNum) {
   return size_t(aNum) * 1024_KiB;
 }
 
-constexpr size_t operator"" _MiB(long double aNum) {
+constexpr size_t operator""_MiB(long double aNum) {
   return size_t(aNum * 1024_KiB);
 }
 

xpcom/string/nsTLiteralString.h

@@ -91,8 +91,8 @@ class nsTLiteralString : public mozilla::detail::nsTStringRepr<T> {
 // any non-private use of that constructor would get into the codebase.
 #if defined(__clang__)
  private:
-  friend constexpr auto operator"" _ns(const char* aStr, std::size_t aLen);
-  friend constexpr auto operator"" _ns(const char16_t* aStr, std::size_t aLen);
+  friend constexpr auto operator""_ns(const char* aStr, std::size_t aLen);
+  friend constexpr auto operator""_ns(const char16_t* aStr, std::size_t aLen);
 #else
  public:
 #endif