gnu: commencement: Turn off RUNPATH checks for 'gcc-final'.

* gnu/packages/commencement.scm (gcc-final)[arguments]: Add
  #:validate-runpath? #f.

gnu/packages/commencement.scm

@@ -500,6 +500,11 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%"
 
        #:allowed-references ("out" "lib" ,glibc-final)
 
+       ;; Things like libasan.so and libstdc++.so NEED ld.so and/or
+       ;; libgcc_s.so but RUNPATH is empty.  This is a false positive, so turn
+       ;; it off.
+       #:validate-runpath? #f
+
        ;; Build again GMP & co. within GCC's build process, because it's hard
        ;; to do outside (because GCC-BOOT0 is a cross-compiler, and thus
        ;; doesn't honor $LIBRARY_PATH, which breaks `gnu-build-system'.)