Test disassemble with both modes active

Author: arsenm

llvm/test/MC/Disassembler/AMDGPU/gfx10_vopc.txt

@@ -1,6 +1,6 @@
 # RUN: llvm-mc -triple=amdgcn -mcpu=gfx1010 -mattr=+wavefrontsize32 -disassemble -show-encoding < %s | FileCheck -strict-whitespace -check-prefix=W32 %s
 # RUN: llvm-mc -triple=amdgcn -mcpu=gfx1010 -mattr=+wavefrontsize64 -disassemble -show-encoding < %s | FileCheck -strict-whitespace -check-prefix=W64 %s
-
+# RUN: llvm-mc -triple=amdgcn -mcpu=gfx1010 -mattr=+wavefrontsize32,+wavefrontsize64 -disassemble -show-encoding < %s | FileCheck -strict-whitespace -check-prefix=W32 %s
 
 # W32: v_cmp_class_f32_e32 vcc_lo, -1, v2      ; encoding: [0xc1,0x04,0x10,0x7d]
 # W64: v_cmp_class_f32_e32 vcc, -1, v2         ; encoding: [0xc1,0x04,0x10,0x7d]