Bump regalloc.rs to 0.0.26;

And adapt to regalloc.rs API change to provide the exact number of vregs.

cranelift/codegen/Cargo.toml

@@ -25,7 +25,7 @@ smallvec = { version = "1.0.0" }
 thiserror = "1.0.4"
 byteorder = { version = "1.3.2", default-features = false }
 peepmatic-runtime = { path = "../peepmatic/crates/runtime", optional = true, version = "0.1.0" }
-regalloc = "0.0.25"
+regalloc = "0.0.26"
 # It is a goal of the cranelift-codegen crate to have minimal external dependencies.
 # Please don't add any unless they are essential to the task of creating binary
 # machine code. Integration tests that need external dependencies can be

cranelift/codegen/src/machinst/vcode.rs

@@ -465,8 +465,8 @@ impl<I: VCodeInst> RegallocFunction for VCode<I> {
         insn.is_move()
     }
 
-    fn get_vreg_count_estimate(&self) -> Option<usize> {
-        Some(self.vreg_types.len())
+    fn get_num_vregs(&self) -> usize {
+        self.vreg_types.len()
     }
 
     fn get_spillslot_size(&self, regclass: RegClass, vreg: VirtualReg) -> u32 {