Do IWYU for pdf_fuzzer_init_public.cc.

On Linux, #include <linux/limits.h> for PATH_MAX. Found by building with
GCC.

Change-Id: I39c13ced24f03ac228d4b6a9e9f0f8e9e449a6c8
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/55990
Auto-Submit: Lei Zhang <thestig@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
diff --git a/testing/fuzzers/pdf_fuzzer_init_public.cc b/testing/fuzzers/pdf_fuzzer_init_public.cc
index 63bf6ae..1423635 100644
--- a/testing/fuzzers/pdf_fuzzer_init_public.cc
+++ b/testing/fuzzers/pdf_fuzzer_init_public.cc
@@ -20,6 +20,7 @@
 #elif defined(__APPLE__)
 #include <mach-o/dyld.h>
 #else  // Linux
+#include <linux/limits.h>
 #include <unistd.h>
 #endif  // _WIN32