Miscellaneous inlining improvements

Add `#[inline]` to a few trivial non-generic methods from a perf report
that otherwise wouldn't be candidates for inlining.

compiler/rustc_query_system/src/query/job.rs

@@ -84,6 +84,7 @@ pub struct QueryJob {
 
 impl QueryJob {
     /// Creates a new query job.
+    #[inline]
     pub fn new(id: QueryJobId, span: Span, parent: Option<QueryJobId>) -> Self {
         QueryJob {
             id,
@@ -106,6 +107,7 @@ impl QueryJob {
     ///
     /// This does nothing for single threaded rustc,
     /// as there are no concurrent jobs which could be waiting on us
+    #[inline]
     pub fn signal_complete(self) {
         #[cfg(parallel_compiler)]
         {

compiler/rustc_query_system/src/query/mod.rs

@@ -81,6 +81,7 @@ pub struct QuerySideEffects {
 }
 
 impl QuerySideEffects {
+    #[inline]
     pub fn is_empty(&self) -> bool {
         let QuerySideEffects { diagnostics } = self;
         diagnostics.is_empty()