Optimization for miranda

• Optimize cava and edge detection schedules (CPU schedules are multi-core now).
• Add fork-extend pass to make fork dimensions multiple of some number (closes #28 (closed)).
• Make GCM add extra dimensions to per-thread arrays in fork-joins.
• Make GCM allocate extra memory for calls in parallel, make RT backend use different memories per parallel call.
• Make not finding xdot binary crash the compiler.
• Some misc. fixes.
• Add conv-like fork-join test.

juno_samples/edge_detection/src/cpu.sch

@@ -45,7 +45,8 @@ fork-tile[4, 1, false, false](par);
 fork-tile[4, 0, false, false](par);
 fork-interchange[1, 2](par);
 let split = fork-split(par);
-let laplacian_estimate_body = outline(split._1_laplacian_estimate.fj2);
+let body = split._1_laplacian_estimate.fj2 | laplacian_estimate.shr1 | laplacian_estimate.shr2;
+let laplacian_estimate_body = outline(body);
 fork-coalesce(laplacian_estimate, laplacian_estimate_body);
 simpl!(laplacian_estimate, laplacian_estimate_body);
 
@@ -61,7 +62,8 @@ fork-tile[4, 1, false, false](par);
 fork-tile[4, 0, false, false](par);
 fork-interchange[1, 2](par);
 let split = fork-split(par);
-let zero_crossings_body = outline(split._2_zero_crossings.fj2);
+let body = split._2_zero_crossings.fj2 | zero_crossings.shr1 | zero_crossings.shr2;
+let zero_crossings_body = outline(body);
 fork-coalesce(zero_crossings, zero_crossings_body);
 simpl!(zero_crossings, zero_crossings_body);