Use local_rustflags where appropriate

Using local rustflags passed via `cargo rustc` has the advantage,
that they are not set for dependencies.
This is mostly benenficial in workspaces, where different crates link
different C dependencies, but share common rust dependencies.
If the RUSTFLAGS environment variable is used this will cause rebuilds
of the common rust dependencies, since the RUSTFLAGS  differ.
When passing rustflags via cargo rustc, this does not happen, since they
only affects the main crate.

cmake/Corrosion.cmake

@@ -347,13 +347,13 @@ function(_add_cargo_build)
         list(APPEND corrosion_cc_rs_flags "SDKROOT=${CMAKE_OSX_SYSROOT}")
     endif()
 
-    corrosion_add_target_rustflags("${target_name}" "$<$<BOOL:${corrosion_link_args}>:-Clink-args=${corrosion_link_args}>")
+    corrosion_add_target_local_rustflags("${target_name}" "$<$<BOOL:${corrosion_link_args}>:-Clink-args=${corrosion_link_args}>")
 
     # todo: this should probably also be guarded by if_not_host_build_condition.
     if(COR_NO_STD)
-        corrosion_add_target_rustflags("${target_name}" "-Cdefault-linker-libraries=no")
+        corrosion_add_target_local_rustflags("${target_name}" "-Cdefault-linker-libraries=no")
     else()
-        corrosion_add_target_rustflags("${target_name}" "-Cdefault-linker-libraries=yes")
+        corrosion_add_target_local_rustflags("${target_name}" "-Cdefault-linker-libraries=yes")
     endif()
 
     set(global_joined_rustflags "$<JOIN:${global_rustflags_target_property}, >")
@@ -379,7 +379,7 @@ function(_add_cargo_build)
             # Skip adding the linker argument, if the linker is explicitly set, since the
             # explicit_linker_property will not be set when this function runs.
             # Passing this rustflag is necessary for clang.
-            corrosion_add_target_rustflags("${target_name}" "$<$<NOT:$<BOOL:${explicit_linker_property}>>:${rustflag_linker_arg}>")
+            corrosion_add_target_local_rustflags("${target_name}" "$<$<NOT:$<BOOL:${explicit_linker_property}>>:${rustflag_linker_arg}>")
         endif()
     else()
         message(DEBUG "No linker preference for target ${target_name} could be detected.")
@@ -696,8 +696,8 @@ function(corrosion_link_libraries target_name)
             $<TARGET_PROPERTY:${library},LINKER_LANGUAGE>
         )
 
-        corrosion_add_target_rustflags(${target_name} "-L$<TARGET_LINKER_FILE_DIR:${library}>")
-        corrosion_add_target_rustflags(${target_name} "-l$<TARGET_LINKER_FILE_BASE_NAME:${library}>")
+        corrosion_add_target_local_rustflags(${target_name} "-L$<TARGET_LINKER_FILE_DIR:${library}>")
+        corrosion_add_target_local_rustflags(${target_name} "-l$<TARGET_LINKER_FILE_BASE_NAME:${library}>")
     endforeach()
 endfunction(corrosion_link_libraries)