Update to bitflags 2 in the compiler

This involves lots of breaking changes. There are two big changes that
force changes. The first is that the bitflag types now don't
automatically implement normal derive traits, so we need to derive them
manually.

Additionally, bitflags now have a hidden inner type by default, which
breaks our custom derives. The bitflags docs recommend using the impl
form in these cases, which I did.

2 files changed, 3 insertions, 2 deletions

diff --git a/compiler/rustc_session/Cargo.toml b/compiler/rustc_session/Cargo.toml
index 1f51dd6c975..ba8f67982f5 100644
--- a/compiler/rustc_session/Cargo.toml
+++ b/compiler/rustc_session/Cargo.toml
@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 getopts = "0.2"
 rustc_ast = { path = "../rustc_ast" }
 rustc_data_structures = { path = "../rustc_data_structures" }
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index e1640d7fca9..89508c77639 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -1021,6 +1021,7 @@ impl OutputFilenames {
 
 bitflags::bitflags! {
     /// Scopes used to determined if it need to apply to --remap-path-prefix
+    #[derive(Clone, Copy, PartialEq, Eq, Hash)]
     pub struct RemapPathScopeComponents: u8 {
         /// Apply remappings to the expansion of std::file!() macro
         const MACRO = 1 << 0;
@@ -1041,7 +1042,7 @@ bitflags::bitflags! {
         /// An alias for macro,unsplit-debuginfo,split-debuginfo-path. This
         /// ensures all paths in compiled executables or libraries are remapped
         /// but not elsewhere.
-        const OBJECT = Self::MACRO.bits | Self::UNSPLIT_DEBUGINFO.bits | Self::SPLIT_DEBUGINFO_PATH.bits;
+        const OBJECT = Self::MACRO.bits() | Self::UNSPLIT_DEBUGINFO.bits() | Self::SPLIT_DEBUGINFO_PATH.bits();
     }
 }