[ARM] Re-enable misspelled RUN: lines in fullfp16.s.
[ARM] Re-enable misspelled RUN: lines in fullfp16.s.

rL364293 committed a couple of lines that just said "// RUN llvm-mc ..."
without the all-important ':' after RUN, so those test lines weren't
actually running anything.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@364305 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm