Merge pull request halide#1055 from halide/thread_safety

Attempt to make the compiler thread-safe.

Relax test timing tolerance

Merge pull request halide#948 from halide/vec-bool-cl

Enable vectorized boolean logic in OpenCL C

Merge pull request halide#931 from halide/typed_create_buffer_t

Typed create buffer_t

Fix incorrect printing of Renderscript target flag as "rs" in Target:…

…:to_string.

Fix Target::to_string test to cover Renderscript and OpenGLCompute.

(Indentation fix in Target::to_string.)

Fix accidental non-member function

Added -Wall to generator build, renamed run to run_blur to avoid shad…

…owing builtin.

GeneratorParamBase needs a copy ctor

It’s rarely used, but if/when it is, assertions will result since
unregister_instance() will fail.

Merge pull request halide#688 from halide/includes

<Halide.h> -> "Halide.h"

Merge pull request halide#496 from halide/ramp_div_mod_simplify_rules

Rework and add new rules for simplifying ramp/x and ramp%x