rust: disable on GCC_PLUGIN_RANDSTRUCT

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ojeda

init/Kconfig

@@ -2059,6 +2059,7 @@ config RUST
 	depends on HAS_RUST
 	depends on !COMPILE_TEST
 	depends on !MODVERSIONS
+	depends on !GCC_PLUGIN_RANDSTRUCT
 	default n
 	help
 	  Enables Rust support in the kernel.

rust/Makefile

@@ -188,9 +188,9 @@ else
 # bindgen relies on libclang to parse C. Ideally, bindgen would support a GCC
 # plugin backend and/or the Clang driver would be perfectly compatible with GCC.
 #
-# For the moment, here we are tweaking the flags on the fly. Some config
-# options may not work (e.g. `GCC_PLUGIN_RANDSTRUCT` if we end up using one
-# of those structs).
+# For the moment, here we are tweaking the flags on the fly. This is a hack,
+# and some kernel configurations may not work (e.g. `GCC_PLUGIN_RANDSTRUCT`
+# if we end up using one of those structs).
 bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \
 	-mskip-rax-setup -mgeneral-regs-only -msign-return-address=% \
 	-mindirect-branch=thunk-extern -mindirect-branch-register -mrecord-mcount \