Auto merge of rust-lang#3196 - RalfJung:provenance-gc, r=RalfJung

explain tests that disable the provenance GC

Author: bors

src/tools/miri/tests/fail/tree_borrows/reserved/cell-protected-write.rs

@@ -1,3 +1,4 @@
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 
 // Check how a Reserved with interior mutability

src/tools/miri/tests/fail/tree_borrows/reserved/int-protected-write.rs

@@ -1,3 +1,4 @@
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 
 #[path = "../../../utils/mod.rs"]

src/tools/miri/tests/pass/tree_borrows/cell-alternate-writes.rs

@@ -1,3 +1,4 @@
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 #[path = "../../utils/mod.rs"]
 #[macro_use]

src/tools/miri/tests/pass/tree_borrows/end-of-protector.rs

@@ -1,3 +1,4 @@
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 
 // Check that a protector goes back to normal behavior when the function

src/tools/miri/tests/pass/tree_borrows/formatting.rs

@@ -1,3 +1,4 @@
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 
 #[path = "../../utils/mod.rs"]

src/tools/miri/tests/pass/tree_borrows/reborrow-is-read.rs

@@ -1,3 +1,4 @@
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 
 #[path = "../../utils/mod.rs"]

src/tools/miri/tests/pass/tree_borrows/reserved.rs

@@ -1,3 +1,4 @@
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 
 #[path = "../../utils/mod.rs"]

src/tools/miri/tests/pass/tree_borrows/unique.rs

@@ -1,4 +1,5 @@
 //@revisions: default uniq
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 //@[uniq]compile-flags: -Zmiri-unique-is-unique
 

src/tools/miri/tests/pass/tree_borrows/vec_unique.rs

@@ -1,4 +1,5 @@
 //@revisions: default uniq
+// We disable the GC for this test because it would change what is printed.
 //@compile-flags: -Zmiri-tree-borrows -Zmiri-provenance-gc=0
 //@[uniq]compile-flags: -Zmiri-unique-is-unique