emulators/citra: unbreak on i386 with clang 5+

externals/cryptopp/cryptopp/sha.cpp:1005:5: error: invalid operand for instruction

ASJ(    jnz,     0, b)
^

externals/cryptopp/cryptopp/cpu.h:623:23: note: expanded from macro 'ASJ'

#define ASJ(x, y, z) GNU_ASJ(x, y, z)
                     ^

externals/cryptopp/cryptopp/cpu.h:617:27: note: expanded from macro 'GNU_ASJ'

#define GNU_ASJ(x, y, z) #x " " #y #z ";" NEW_LINE
                         ^

<scratch space>:34:2: note: expanded from here
"jnz"
^
<inline asm>:80:1: note: instantiated into assembly here
jnz 0b;
^

Reported by: pkg-fallout
Obtained from: upstream (cryptopp 7.1.0)