* SPARC peephole: check that result of GetNextInstructionUsingReg is actually an instruction, because GetNextInstruction can stop at a label. Resolves #26798.
The same issue on MIPS targets was fixed by r28380, but I forgot to apply it also to SPARC.

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@28722 3ad0048d-3df7-0310-abae-a5850022a9f2