Fix clippy warnings.

This commit fixes the current set of (stable) clippy warnings in the repo.

cranelift/codegen/src/ir/globalvalue.rs

@@ -70,7 +70,7 @@ impl GlobalValueData {
     /// Assume that `self` is an `GlobalValueData::Symbol` and return its name.
     pub fn symbol_name(&self) -> &ExternalName {
         match *self {
-            GlobalValueData::Symbol { ref name, .. } => name,
+            Self::Symbol { ref name, .. } => name,
             _ => panic!("only symbols have names"),
         }
     }
@@ -78,11 +78,8 @@ impl GlobalValueData {
     /// Return the type of this global.
     pub fn global_type(&self, isa: &dyn TargetIsa) -> Type {
         match *self {
-            GlobalValueData::VMContext { .. } | GlobalValueData::Symbol { .. } => {
-                isa.pointer_type()
-            }
-            GlobalValueData::IAddImm { global_type, .. }
-            | GlobalValueData::Load { global_type, .. } => global_type,
+            Self::VMContext { .. } | Self::Symbol { .. } => isa.pointer_type(),
+            Self::IAddImm { global_type, .. } | Self::Load { global_type, .. } => global_type,
         }
     }
 }
@@ -90,8 +87,8 @@ impl GlobalValueData {
 impl fmt::Display for GlobalValueData {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            GlobalValueData::VMContext => write!(f, "vmctx"),
-            GlobalValueData::Load {
+            Self::VMContext => write!(f, "vmctx"),
+            Self::Load {
                 base,
                 offset,
                 global_type,
@@ -104,12 +101,12 @@ impl fmt::Display for GlobalValueData {
                 base,
                 offset
             ),
-            GlobalValueData::IAddImm {
+            Self::IAddImm {
                 global_type,
                 base,
                 offset,
             } => write!(f, "iadd_imm.{} {}, {}", global_type, base, offset),
-            GlobalValueData::Symbol {
+            Self::Symbol {
                 ref name,
                 offset,
                 colocated,