[PATCH V7 1/4] rust: Fix a race condition in Makefile

["Mukesh Kumar Chaurasiya (IBM)" <mkchauras@gmail.com>]

When compiling with -j1 flag in powerpc, the libproc_macro finds the
libcore.rmeta both in toolchain and local rust directory. libproc_macro
should use the toolchain provided libcore.rmeta.

So for this, make libproc_macro2 libquote and libsyn dependent on core.o
so that libcore.rmeta is generated after these 3 files are done
compiling.

Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
 rust/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/rust/Makefile b/rust/Makefile
index 9801af2e1e02..8e62f6fcf94f 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -650,7 +650,8 @@ $(obj)/core.o: private skip_flags = $(core-skip_flags)
 $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym))
 $(obj)/core.o: private rustc_target_flags = $(core-flags)
 $(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs \
-    $(wildcard $(objtree)/include/config/RUSTC_VERSION_TEXT) FORCE
+    $(wildcard $(objtree)/include/config/RUSTC_VERSION_TEXT) FORCE \
+    | $(obj)/libproc_macro2.rlib $(obj)/libquote.rlib $(obj)/libsyn.rlib FORCE
 	+$(call if_changed_rule,rustc_library)
 ifneq ($(or $(CONFIG_X86_64),$(CONFIG_X86_32)),)
 $(obj)/core.o: scripts/target.json
-- 
2.53.0