[AddressLowering] Loosen assert for partial_apply.

Full apply instructions have the same number of arguments as the callee
has parameters.  Partial apply instructions have some number less than
or equal to the number of callee parameters.

Author: nate-chandler

lib/SILOptimizer/Mandatory/AddressLowering.cpp

@@ -2190,8 +2190,11 @@ bool CallArgRewriter::rewriteArguments() {
   bool changed = false;
 
   auto origConv = apply.getSubstCalleeConv();
-  assert(apply.getNumArguments() == origConv.getNumParameters() &&
-         "results should not yet be rewritten");
+  assert((apply.getNumArguments() == origConv.getNumParameters() &&
+          apply.asFullApplySite()) ||
+         (apply.getNumArguments() <= origConv.getNumParameters() &&
+          !apply.asFullApplySite()) &&
+             "results should not yet be rewritten");
 
   for (unsigned argIdx = apply.getCalleeArgIndexOfFirstAppliedArg(),
                 endArgIdx = argIdx + apply.getNumArguments();