Bug 7458: Adapt to changed LLVM intrinsic signatures

* sources/dfmc/llvm-back-end/llvm-primitives-machine-word.dylan
  (primitive-machine-word-count-low-zeros,
   primitive-machine-word-count-high-zeros): Supply new required arguments
   to the llvm.cttz and llvm.ctlz intrinsics.
Bug 7440 7558: Change llvm-builder optional parameters convention

* sources/lib/llvm/llvm-builder.dylan
  (ins--phi): Change to take a sequence of operand values.
  (ins--phi*): New "spread arguments" convenience function taking operand
   values as #rest operands.
  (ins--switch): Change to take a sequence of jump table values.
  (ins--switch*): New "spread arguments" convenience function taking operand
   values as #rest operands.

* sources/lib/llvm/llvm-library.dylan
  (module llvm-builder): Export ins--phi* and ins--switch*.

* sources/lib/llvm/tests/specification.dylan
  (module-spec llvm-builder): Adapt to changed signatures and new functions.

* sources/lib/llvm/tests/llvm-builder-test.dylan
  (function-test ins--phi): New (unimplemented) test.
  (function-test ins--phi*): Renamed from previous ins--phi test.
  (function-test ins--switch): New (unimplemented) test.
  (function-test ins--switch*): Renamed from previous ins--phi test.

* sources/dfmc/llvm-back-end/llvm-primitives-basic.dylan: Change for
  new conventions.

* sources/dfmc/llvm-back-end/llvm-primitives-lambda.dylan: Change for
  new conventions.

* sources/dfmc/llvm-back-end/llvm-primitives-machine-word.dylan:
  Change for new conventions.

* sources/dfmc/llvm-back-end/llvm-primitives-symbol.dylan: Change for
  new conventions.

* sources/dfmc/llvm-back-end/llvm-varargs.dylan: Change for new
  conventions.

* sources/dfmc/llvm-back-end/llvm-entry-points.dylan: Change for new
  conventions.

* sources/dfmc/llvm-back-end/llvm-emit-type-check.dylan: Change for
  new conventions.

* sources/dfmc/llvm-back-end/llvm-emit-computation.dylan: Change for
  new conventions.