irbuild read input file accorrding to its file suffix.
irbuild given -b option will write output file in binary file format
irbuild can be controlled to only output specific functions via -dumpfunc= option.
Binary version of .mpl file uses .bpl file suffix.
Ascii version of .mplt file uses .tmpl file suffix.
Support typeattr field in MIRArrayType in Maple IR parser.
This patch causes .mplt to be incompatible with earlier versions.
Front-ends producing .mplt need to be rebuilt with this version before testing.
Front-ends can continue to output .mpl as before, but they can be made to output .bpl controlled via command line option.
Refer to maple_ir/src/driver.cpp on how to output .bpl.
Maple driver also accepts .bpl as input.