CrashHandler calls strsignal on linux

tools/CrashHandler.cpp

 #include "CrashHandler.h"
 
 #include "SkTypes.h"
 
 #include <stdlib.h>
 
 #if defined(SK_BUILD_FOR_MAC)
 
 // We only use local unwinding, so we can define this to select a faster implementation.
 #define UNW_LOCAL_ONLY
@@ skipping 30 matching lines @@
 
 // We'd use libunwind here too, but it's a pain to get installed for both 32 and 64 bit on bots.
 // Doesn't matter much: catchsegv is best anyway.
 #include <execinfo.h>
 
 static void handler(int sig) {
     static const int kMax = 64;
     void* stack[kMax];
     const int count = backtrace(stack, kMax);
 
-    SkDebugf("\nSignal %d:\n", sig);
+    SkDebugf("\nSignal %d [%s]:\n", sig, strsignal(sig));
     backtrace_symbols_fd(stack, count, 2/*stderr*/);
 
     // Exit NOW.  Don't notify other threads, don't call anything registered with atexit().
     _Exit(sig);
 }
 
 #endif
 
 #if defined(SK_BUILD_FOR_MAC) || (defined(SK_BUILD_FOR_UNIX) && !defined(SK_BUILD_FOR_NACL))
 #include <signal.h>
@@ skipping 101 matching lines @@
 
 void SetupCrashHandler() {
     SetUnhandledExceptionFilter(handler);
 }
 
 #else
 
 void SetupCrashHandler() { }
 
 #endif