Fix missing space in lossy provenance cast lint

compiler/rustc_typeck/src/check/cast.rs

@@ -1012,7 +1012,7 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                     err.help(msg);
                 }
                 err.help(
-                    "if you can't comply with strict provenance and need to expose the pointer\
+                    "if you can't comply with strict provenance and need to expose the pointer \
                     provenance you can use `.expose_addr()` instead"
                 );
 

src/test/ui/lint/lint-strict-provenance-lossy-casts.stderr

@@ -9,15 +9,15 @@ note: the lint level is defined here
    |
 LL | #![deny(lossy_provenance_casts)]
    |         ^^^^^^^^^^^^^^^^^^^^^^
-   = help: if you can't comply with strict provenance and need to expose the pointerprovenance you can use `.expose_addr()` instead
+   = help: if you can't comply with strict provenance and need to expose the pointer provenance you can use `.expose_addr()` instead
 
 error: under strict provenance it is considered bad style to cast pointer `*const u8` to integer `u32`
   --> $DIR/lint-strict-provenance-lossy-casts.rs:9:22
    |
 LL |     let addr_32bit = &x as *const u8 as u32;
    |                      ^^^^^^^^^^^^^^^^^^^^^^ help: use `.addr()` to obtain the address of a pointer: `(&x as *const u8).addr() as u32`
    |
-   = help: if you can't comply with strict provenance and need to expose the pointerprovenance you can use `.expose_addr()` instead
+   = help: if you can't comply with strict provenance and need to expose the pointer provenance you can use `.expose_addr()` instead
 
 error: aborting due to 2 previous errors