asan: Use #if to test CAN_SANITIZE_LEAKS

The `if (0)` isn't necessarily optimized out so as not to create
a link-time reference to LSan runtime functions that might not
exist.  So use explicit conditional compilation instead.

Reviewed By: phosek

Differential Revision: https://reviews.llvm.org/D88173

Author: frobtech

compiler-rt/lib/asan/asan_rtl.cpp

@@ -498,10 +498,10 @@ static void AsanInitInternal() {
   force_interface_symbols();  // no-op.
   SanitizerInitializeUnwinder();
 
-  if (CAN_SANITIZE_LEAKS) {
-    __lsan::InitCommonLsan();
-    InstallAtExitCheckLeaks();
-  }
+#if CAN_SANITIZE_LEAKS
+  __lsan::InitCommonLsan();
+  InstallAtExitCheckLeaks();
+#endif
 
 #if CAN_SANITIZE_UB
   __ubsan::InitAsPlugin();

compiler-rt/lib/lsan/lsan_common_fuchsia.cpp

@@ -51,7 +51,7 @@ void ProcessPlatformSpecificAllocations(Frontier *frontier) {}
 // behavior and causes rare race conditions.
 void HandleLeaks() {}
 
-// This is defined differently in asan_fuchsiap.cpp and lsan_fuchsia.cpp.
+// This is defined differently in asan_fuchsia.cpp and lsan_fuchsia.cpp.
 bool UseExitcodeOnLeak();
 
 int ExitHook(int status) {