mk: Rename CFG_COMPILER to CFG_COMPILER_HOST_TRIPLE

Much clearer

mk/target.mk

@@ -11,7 +11,7 @@
 # This is the compile-time target-triple for the compiler. For the compiler at
 # runtime, this should be considered the host-triple. More explanation for why
 # this exists can be found on issue #2400
-export CFG_COMPILER
+export CFG_COMPILER_HOST_TRIPLE
 
 # The standard libraries should be held up to a higher standard than any old
 # code, make sure that these common warnings are denied by default. These can
@@ -68,7 +68,7 @@ $(foreach host,$(CFG_HOST),						    \
 # $(4) is the crate name
 define RUST_TARGET_STAGE_N
 
-$$(TLIB$(1)_T_$(2)_H_$(3))/stamp.$(4): CFG_COMPILER = $(2)
+$$(TLIB$(1)_T_$(2)_H_$(3))/stamp.$(4): CFG_COMPILER_HOST_TRIPLE = $(2)
 $$(TLIB$(1)_T_$(2)_H_$(3))/stamp.$(4):				    \
 		$$(CRATEFILE_$(4))				    \
 		$$(CRATE_FULLDEPS_$(1)_T_$(2)_H_$(3)_$(4))	    \

mk/tests.mk

@@ -350,7 +350,7 @@ else
 TESTDEP_$(1)_$(2)_$(3)_$(4) = $$(RSINPUTS_$(4))
 endif
 
-$(3)/stage$(1)/test/$(4)test-$(2)$$(X_$(2)): CFG_COMPILER = $(2)
+$(3)/stage$(1)/test/$(4)test-$(2)$$(X_$(2)): CFG_COMPILER_HOST_TRIPLE = $(2)
 $(3)/stage$(1)/test/$(4)test-$(2)$$(X_$(2)):				\
 		$$(CRATEFILE_$(4)) \
 		$$(TESTDEP_$(1)_$(2)_$(3)_$(4))

src/librustc/driver/driver.rs

@@ -800,7 +800,7 @@ pub fn host_triple() -> ~str {
     // Instead of grabbing the host triple (for the current host), we grab (at
     // compile time) the target triple that this rustc is built with and
     // calling that (at runtime) the host triple.
-    (env!("CFG_COMPILER")).to_owned()
+    (env!("CFG_COMPILER_HOST_TRIPLE")).to_owned()
 }
 
 pub fn build_session_options(matches: &getopts::Matches) -> session::Options {