Remove the test for whether the uninstalled dtable is present from

objc_msgSend().  If the class does have the uninstalled dtable, then every
method will be the nil slot and so, after navigating the dtable we will
discover that it is nil and go into the slow path.  The cost of this change is
a slight slowdown in the first message sent to every class.  The benefit is
that every subsequent message send needs one fewer memory access and one fewer
conditional jump.

objc_msgSend.x86-32.S

@@ -15,8 +15,6 @@
 1:                                        # classLoaded
 	movl  \sel(%esp), %ecx
 	mov   DTABLE_OFFSET(%eax), %eax       # Load the dtable from the class
-	cmpl  uninstalled_dtable, %eax        # If this is not (yet) a valid dtable
-	je    5f                              # Do a slow lookup
 	
 	mov   (%ecx), %ecx                    # Load the selector index
 

objc_msgSend.x86-64.S

@@ -20,8 +20,6 @@
 	mov   (\receiver), %r10               # Load the dtable from the class
 1:                                        # classLoaded
 	mov   DTABLE_OFFSET(%r10), %r10       # Load the dtable from the class
-	cmpq  uninstalled_dtable(%rip), %r10  # If this is not (yet) a valid dtable
-	je    5f                              # Do a slow lookup
 	
 	push  %r12
 	push  %r13