Add CPack configuration for debian packages

Allows to automatically generate .deb based on current generated `install`
target. Some of package settings are taken from exiting CMake variables, some
from host system.
Possible fix for issue #594.

DMD always uses the value type for name mangling of templates. If the type is defined in the template
and the value type differs (e.g. parameter type is long and constant 4 (int) is used) then LDC got
confused about this fact. As a result, sometimes the parameter type and sometime the value type was used.

This commit changes the name mangling to use the parameter type, if possible. This is incompatible with
DMD but solves the issue. The related DMD error is https://issues.dlang.org/show_bug.cgi?id=12720
Merge pull request #580 from Dicebot/deb-package

Add CPack configuration for debian packages
Merge branch 'master' into merge-2.064
Add druntime changes
Use LLVM 3.4 for release multilib build
Merge pull request #600 from klickverbot/system-libs-3.5

FindLLVM: Pick up system libraries on LLVM 3.5+.
Remove some casts.
Fix assertion error with debug build in LLVM 3.5

This is one part of issue #607.
Fix LLVM 3.5 dependency
Fix LLVM 3.5 build
Remove unused member
Fix dmd test template2962 by removing nestedVars.

nestedVars was always a copy of closureVars. There was no point to it
existing.
Merge pull request #618 from ckamm/fix-nestedvars

Fix dmd test template2962 by removing nestedVars.
Make intrinsic parameter errors in CallExp::toElem() fatal.

Returning null will crash just about any other glue layer code.

Ideally, we'd catch those during semantic analysis (glue layer
errors are always to be avoided due to speculative compilation),
but this at least avoids the segfaults.
Reject non-integer atomic load/store during codegen.

This avoids hitting an LLVM assert during codegen.
Fix atomic{Load, Store}() for struct types.

GitHub: Fixes #616.
Merge branch 'master' into merge-2.064

Conflicts:
	gen/nested.cpp
Merge pull request #619 from klickverbot/core-atomic-struct

Fix atomic{Load, Store}() for struct types.
Merge branch 'master' into merge-2.064

Conflicts:
	runtime/druntime