Added Singlepass backend

lib/compiler-singlepass/src/config.rs

@@ -0,0 +1,64 @@
+// Allow unused imports while developing
+#![allow(unused_imports, dead_code)]
+
+use crate::compiler::SinglepassCompiler;
+use wasmer_compiler::{Compiler, CompilerConfig, CpuFeature, Features, Target};
+
+#[derive(Clone)]
+pub struct SinglepassConfig {
+    /// Enable NaN canonicalization.
+    ///
+    /// NaN canonicalization is useful when trying to run WebAssembly
+    /// deterministically across different architectures.
+    pub enable_nan_canonicalization: bool,
+
+    features: Features,
+    target: Target,
+}
+
+impl SinglepassConfig {
+    /// Creates a new configuration object with the default configuration
+    /// specified.
+    pub fn new() -> Self {
+        Self {
+            enable_nan_canonicalization: true,
+            features: Default::default(),
+            target: Default::default(),
+        }
+    }
+}
+
+impl CompilerConfig for SinglepassConfig {
+    /// Gets the WebAssembly features
+    fn features(&self) -> &Features {
+        &self.features
+    }
+
+    /// Gets the WebAssembly features, mutable
+    fn features_mut(&mut self) -> &mut Features {
+        &mut self.features
+    }
+
+    /// Gets the target that we will use for compiling
+    /// the WebAssembly module
+    fn target(&self) -> &Target {
+        &self.target
+    }
+
+    /// Gets the target that we will use for compiling
+    /// the WebAssembly module, mutable
+    fn target_mut(&mut self) -> &mut Target {
+        &mut self.target
+    }
+
+    /// Transform it into the compiler
+    fn compiler(&self) -> Box<dyn Compiler> {
+        Box::new(SinglepassCompiler::new(&self))
+    }
+}
+
+impl Default for SinglepassConfig {
+    fn default() -> SinglepassConfig {
+        SinglepassConfig::new()
+    }
+}