posix.mak: Clean up /tmp test directory unconditionally

Author: CyberShadow

posix.mak

@@ -361,9 +361,11 @@ unittest/%.run : $(ROOT)/unittest/test_runner
 # For example: "make std/algorithm/mutation.test"
 # The mktemp business is needed so .o files don't clash in concurrent unittesting.
 %.test : %.d $(LIB)
-	T=`mktemp -d /tmp/.dmd-run-test.XXXXXX` && \
-	  $(DMD) -od$$T $(DFLAGS) -main -unittest $(LIB) -defaultlib= -debuglib= $(LINKDL) -cov -run $< && \
-	  rm -rf $$T
+	T=`mktemp -d /tmp/.dmd-run-test.XXXXXX` &&                                                              \
+	  (                                                                                                     \
+	    $(DMD) -od$$T $(DFLAGS) -main -unittest $(LIB) -defaultlib= -debuglib= $(LINKDL) -cov -run $< ;     \
+	    RET=$$? ; rm -rf $$T ; exit $$RET                                                                   \
+	  )
 
 # Target for quickly unittesting all modules and packages within a package,
 # transitively. For example: "make std/algorithm.test"