Fix generation of temp var shape (especially for temp vars with base shape)

Should fix https://github.com/inducer/loopy/issues/52.

cc @dokempf

See merge request !30

Should fix https://github.com/inducer/loopy/issues/50.

Set based type inference



See merge request !27

Replace wildcard dependencies by kernel query language

Any given dependencies will be
* treated as a kernel query language match expression
* afterwards treated as a list of instruction IDs to find a match

To that end, the splitting of dependencies from textual language is delayed
until dependency resolution in make_kernel.

The previously implemented wildcard matching is completely
superseded by this mechanism (IMO without any semantics changes).

See merge request !13

Fix iname matching kernel query language

2 bugs:
* a C&P bug in interning (harmless)
* wrong field of instructions is accessed to actually match inames

Previously using iname to match instructions threw an AttributeError.

See merge request !28

2 bugs:
* a C&P bug in interning (harmless)
* wrong field of instructions is accessed to actually match inames

Previously using iname to match instructions threw an AttributeError.

dep_query= allows the specification of instruction dependencies with
an arbitrary kernel query string. After parsing, a MatchExpression
object is created and is kept in the depends_on frozenset of the instruction.
When the kernel is created, those match expressions are resolved and the
IDs of all matching instructions are instead added to the frozenset.

When not using the textual assignment language, you can hand-construct
the MatchExpression object and put it into the depends_on frozenset.

This reverts commit 413fc2bb.

Conflicts:
	loopy/kernel/creation.py

Centralize everything to do with type inference in a single file



See merge request !26

to_loopy_type: specify target



See merge request !25

Generalize add_dependency



See merge request !24

Allow specifying target in to_loopy_type, so that target-specific (e.g. vector) types become parseable

[bugfix] Define the comment field of barrier

The scheduler uses it, so we need to set it:

```
File ".../loopy/codegen/control.py", line 154, in generate_code_for_sched_index
    sched_item.kind, sched_item.comment)
AttributeError: comment
```

See merge request !23

The scheduler uses it, so we need to set it.