Disable compiler warning flag for set but unused variable

Needed since clang is now using -Wunused-but-set-variable.

Bug: pdfium:1691
Change-Id: I085a60d7a60bdbb38477766237a1809d82a09577

1 files changed, 3 insertions, 0 deletions

diff --git a/BUILD.gn b/BUILD.gn
index 2c6981e6..ebd8b7fe 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -78,6 +78,9 @@ config("nasm_config") {
 
       # NASM sometimes uses uninitialized values.
       "-Wno-uninitialized",
+
+      # NASM sometimes set variables but doesn't use them.
+      "-Wno-unused-but-set-variable",
     ]
   } else if (is_win) {
     # Please note that's a slightly different set of warnings.