Don't print a label for the first MBB in a function.

Compile this:

%_2E_str_8 = external global [75 x sbyte]
implementation   ; Functions:
declare int %printf(sbyte*, ...)
void %test()
        %tmp.101 = call int (sbyte*, ...)* %printf( sbyte* getelementptr ([75 x sbyte]* %_2E_str_8, int 0, int 0) )             ; <int> [#uses=0]
        unreachable
}

to this:

main_endif_2E_8:
        save -96, %o6, %o6
        sethi %hi(_2E_str_8), %l0
        add %l0, %lo(_2E_str_8), %o0
        call printf
        nop

instead of this:

main_endif_2E_8:
        save -96, %o6, %o6
        sethi %hi(_2E_str_8), %l0
        or %g0, %lo(_2E_str_8), %l1   ;; extra instruction
        add %l1, %l0, %o0
        call printf
        nop

llvm-svn: 25335