build: remove setting libdirs in premake4.lua

"libdirs { libdir }" in the main premake4.lua file causes Debug_x32
directory to be added for the libdirs for all builds. I think that's a
bug in premake, as at the same place setting, say, "targetdir" works
fine.

However, setting "libdir" to "libdirs" is not needed at all, so let's remove it.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@iki.fi>
build: use path.join() for objdir

use path.join() to set objdir.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@iki.fi>
CppParser: Fix compilation warning

Fix the following warning:

warning: backslash-newline at end of file [enabled by default]

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@iki.fi>
ParserGen: fix compilation warning

Fix the following warning:

ParserGen.cs(208,26): warning CS0618: `CppSharp.AST.Declaration.Ignore' is obsolete: `Replace set by ExplicitlyIgnore(). Replace get by GenerationKind == GenerationKind.None.'

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@iki.fi>
build: add os.is_linux()

Add function to detect if running on linux.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@iki.fi>
ParserGen: print what is being generated

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@iki.fi>
AST: Fix compilation warning

Fix the following warning by removing the new keyword:

src/AST/Type.cs(230,25): warning CS0109: The member `CppSharp.AST.PointerType.IsReference' does not hide an inherited member. The new keyword is not required

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@iki.fi>
Generator: Remove DriverOptions.Is32Bit

DriverOptions.Is32Bit is used to decide whether to use 4 or 8 byte
pointer size in VTable calculations.

Instead of having a settable Is32Bit property, use
TargetInfo.PointerWidth for this. This allows us to remove the whole
Is32Bit property, and the IS_64_BIT define.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@iki.fi>