merge rust-vars and rust-triples to rust-common

Merge two bbclasses that were included in the same places so merge it
into one common file.

classes/cargo.bbclass

@@ -1,7 +1,6 @@
-inherit rust-vars
 # add crate fetch support
 inherit crate-fetch
-inherit rust-triples
+inherit rust-common
 
 # the binary we will use
 CARGO = "cargo"

classes/rust-common.bbclass

@@ -1,3 +1,13 @@
+# Common variables used by all Rust builds
+export rustlibdir = "${libdir}/rust"
+FILES_${PN} += "${rustlibdir}/*.so"
+FILES_${PN}-dev += "${rustlibdir}/*.rlib"
+FILES_${PN}-dbg += "${rustlibdir}/.debug"
+
+RUSTLIB = "-L ${STAGING_LIBDIR}/rust"
+RUSTFLAGS += "-C rpath -C crate_hash=${BB_TASKHASH} ${RUSTLIB}"
+RUSTLIB_DEP ?= "libstd-rs"
+
 # Responseible for taking Yocto triples and converting it to Rust triples
 
 def rust_base_triple(d, thing):

classes/rust-vars.bbclass

@@ -1,8 +0,0 @@
-export rustlibdir = "${libdir}/rust"
-FILES_${PN} += "${rustlibdir}/*.so"
-FILES_${PN}-dev += "${rustlibdir}/*.rlib"
-FILES_${PN}-dbg += "${rustlibdir}/.debug"
-
-RUSTLIB = "-L ${STAGING_LIBDIR}/rust"
-RUSTFLAGS += "-C rpath -C crate_hash=${BB_TASKHASH} ${RUSTLIB}"
-RUSTLIB_DEP ?= "libstd-rs"

classes/rust.bbclass

@@ -1,5 +1,4 @@
-inherit rust-vars
+inherit rust-common
-inherit rust-triples
 
 RUSTC = "rustc"