Bug 7458: Further improve LLVM code generation Makefile test jigs

* Makefile.in (testc, testl): Don't rely on external files.
Bug 7458: Refine LLVM back-end runtime variable generation

* sources/dfmc/llvm-back-end/llvm-primitives.dylan
  (<llvm-runtime-variable-descriptor>): Add a slot to record the
   variable name, and definer adjectives, and remove the slot for the
   global object.
  (runtime-variable-definer): Allow definer adjectives.
  (llvm-runtime-variable): New function for generating global refernces
   to runtime variables (adapted from llvm-runtime-generator).

* sources/dfmc/llvm-back-end/llvm-back-end-library.dylan
  (module dfmc-llvm-back-end): Export llvm-runtime-variable, and don't
   export unneeded <llvm-runtime-variable-descriptor> slot functions.

* sources/dfmc/llvm-back-end/llvm-primitives-debug.dylan
  (primitive primitive-inside-debugger?): Use llvm-runtime-variable.

* sources/dfmc/llvm-back-end/llvm-primitives-os.dylan
  (primitive-runtime-module-handle): Use llvm-runtime-variable.

* sources/app/llvm-runtime-generator/llvm-runtime-generator.dylan
  (generate-runtime-variable): Remove.
  (generate-runtime-heap): Use llvm-runtime-variable.
Bug 7458: Add a member-name slot to <raw-aggregate-member>

* sources/dfmc/modeling/raw-types.dylan
  (<raw-aggregate-member>): Add an optional member-name field for recording
   <&raw-struct-type> member field names.

* sources/dfmc/modeling/modeling-library.dylan
  (module dfmc-modeling): Export member-name.
Bug 7458: Improve LLVM mapping generation for raw struct types

* sources/dfmc/llvm-back-end/llvm-back-end-types.dylan
  (llvm-reference-type on <&raw-struct-type>): Split out field generation
   into add-llvm-struct-member.
  (add-llvm-struct-member): Generate LLVM struct fields for ordinary
   <raw-aggregate-member> and <raw-aggregate-array-member> fields.
Bug 7458: Support a thread-local Thread Environment Block

* sources/dfmc/llvm-back-end/llvm-targets.dylan
  (llvm-thread-local-support?): New method indicating whether LLVM
   thread_local variables are supported on the target platform.

* sources/dfmc/llvm-back-end/llvm-back-end.dylan
  (<llvm-back-end>): Add slots llvm-teb-struct-type and
   %teb-struct-field-index.
  (initialize on <llvm-back-end>): Call initialize-teb-struct-type.

* sources/dfmc/llvm-back-end/llvm-primitives-thread.dylan
  (initialize-teb-struct-type): New method for defining the TEB
   structure type.
  (runtime-variable %teb): New runtime-variable.
  (op--teb): New method for generating a reference to the local TEB.
  (op--teb-getelementptr): New method for generating a reference to
   a specified field of the TEB.

* sources/dfmc/llvm-back-end/llvm-primitives.dylan
  (llvm-runtime-variable): Allow #"<teb>" as a type in runtime-variable
   definitions. Let #f in runtime-variable initializers represent
   zeroinitializer. Allow runtime-variables to be thread-local on platforms
   that support this.

* sources/dfmc/llvm-back-end/llvm-back-end-library.dylan
  (module dfmc-llvm-back-end): Export llvm-thread-local-support? and
   llvm-teb-struct-type.
Bug 7458: Write a TEB struct C header from llvm-runtime-generator

* sources/app/llvm-runtime-generator/llvm-runtime-generator.dylan
  (generate-runtime-header): New function.
  (generate-runtime): Generate a runtime header source file.