Implement first D-specific optimization pass: -simplify-drtcalls. It uses the machinery of the standard -simplify-libcalls pass, but optimizes calls to the D runtime instead of calls to C libraries. At the moment, these optimizations are implemented by this pass: - Avoid the runtime call for `arr.length = newlen` if it can determine that the new length isn't longer than the old one. - Ditto for `cast(T[]) arr` if it will clearly always succeed. (e.g. if the length of the original array is zero, or if the old element size is a multiple of the new element size)

syntax: glob
*.bc
*.diff
*.o
*.obj
*.orig
*.patch
*.a
*.s
*.so
*.rej
Makefile
CMakeFiles
CMakeCache.txt
cmake_install.cmake
.DS_Store

syntax: regexp
^obj/
^tests/dstress/
^tests/reference/
^tango/
^druntime/
^import/
^bin/ldc2?$
^bin/ldc2?\.conf$
^bin/ldc2?\.rebuild\.conf$
^idgen\.make$
^impcnvgen\.make$
^ldc\.make$
^revisions\.pl$
^gen/revisions\.h$
^gen/llvm-version\.h$
^dmd2?/idgen$
^dmd2?/impcnvgen$
^dmd2?/impcnvtab\.c$
^dmd2?/id\.c$
^dmd2?/id\.h$
^tests/runminitest$
^tests/findregressions$
^tests/makewebstatistics$
^tests/mini/obj/