Update to v094r38 release.

byuu says:

I'll post more detailed changes later, but basically:
- fixed Baldur's Gate bug
- guess if no flash ROM ID present (fixes Magical Vacation, many many
  others)
- nall cleanups
- sfc/cartridge major cleanups
- bsxcartridge/"bsx" renamed to mcc/"mcc" after the logic chip it uses
  (consistency with SGB/ICD2)
- ... and more!

nall/GNUmakefile

@@ -81,6 +81,14 @@ ifeq ($(platform),bsd)
   link += -Wl,-rpath=/usr/local/lib/gcc49
 endif
 
+# threading support
+ifeq ($(threaded),true)
+  ifneq ($(filter $(platform),linux bsd),)
+    flags += -pthread
+    link += -lrt
+  endif
+endif
+
 # cross-compilation support
 ifeq ($(arch),x86)
   flags := -m32 $(flags)