This test harness is makefile-driven. It assumes (at least initially) the 
name of the makefile for a given test is "makefile". If it is something else,
such as "Makefile" or "M.example" or anything else the harness needs to know.

In fact, the name is set in the config.xml file, in the options section under
<makefile> </makefile>. This default value can be changed 
permanently by placing a different name in the config.xml file. Or, on a 
per suite or per test basis you can use the -makefile option to 
runtest to use any other name.

The important makefile macro variables, the ones that runtest will either
use the default values or replace based upon runtest options or database
entries are:

SRC  - the path to the test sources. Remember only the makefile is copied to
       the temporary build and run directory
CC/FC- the compiler to invoke
LD   - the linker to use. Usually this is the same as CC/FC.
OPT  - any optimization values to pass to the compiler. These values are
       created based upon the value of flag CXX
RUN  - a driver for each test. This drive value could be just a command such
       as "time", or it could be a simulator used to invoke the executable
       on a remote device. See "-sim" as an argument to runtest.

If the option -printmake is passed to runtest the full make command will
be displayed. Some additional values are passed to the makefile which
include:

EXE  - the expected suffix for an executable file, examples are
       out for linux and exe for windows. Can be used so that makefiles
       can be adapted to different operating systems, such as windows and 
       linux systems by using references similar to a.$(EXE) within the
       makefile.
EXESUFFIX - currently set to the same value as EXE. 
MODE - can be used to distinguish 32- or 64-bit tools, for example. Look
       in the tools database table to see where 32 is set for the mode of
       the gcc compiler. Does not currently affect the behavior of runtest.
TEST - the particular test being invoked 
AS   - use this particular assembler
