Bug 1510113 - Never inline SaveToEnv or SaveWordToEnv. r=karlt

This allows Valgrind to recognize the call stacks to this function,
avoiding Valgrind warnings in intentional leaks in these functions.

Differential Revision: https://phabricator.services.mozilla.com/D13036

--HG--
extra : moz-landing-system : lando

toolkit/xre/CmdLineAndEnvUtils.h

@@ -394,7 +394,7 @@ SetArgv0ToFullBinaryPath(wchar_t* aArgv[])
 #endif // defined(XP_WIN)
 
 // Save literal putenv string to environment variable.
-inline void
+MOZ_NEVER_INLINE inline void
 SaveToEnv(const char *aEnvString)
 {
 #if defined(MOZILLA_INTERNAL_API)

toolkit/xre/nsAppRunner.cpp

@@ -319,7 +319,7 @@ using mozilla::dom::ContentChild;
 using mozilla::intl::LocaleService;
 
 // Save the given word to the specified environment variable.
-static void
+static void MOZ_NEVER_INLINE
 SaveWordToEnv(const char *name, const nsACString & word)
 {
   char *expr = Smprintf("%s=%s", name, PromiseFlatCString(word).get()).release();