auxgm part 1

see also https://github.com/Baystation12/Baystation12/blob/dev/code/modules/xgm/xgm_gas_data.dm

code/datums/diseases/advance/symptoms/heal.dm

@@ -404,8 +404,8 @@
 	if(M.loc)
 		environment = M.loc.return_air()
 	if(environment)
-		plasmamount = environment.get_moles(/datum/gas/plasma)
-		if(plasmamount && plasmamount > GLOB.meta_gas_visibility[/datum/gas/plasma]) //if there's enough plasma in the air to see
+		plasmamount = environment.get_moles(GAS_PLASMA)
+		if(plasmamount && plasmamount > GLOB.meta_gas_visibility[GAS_PLASMA]) //if there's enough plasma in the air to see
 			. += power * 0.5
 	if(M.reagents.has_reagent(/datum/reagent/toxin/plasma))
 		. +=  power * 0.75

code/datums/helper_datums/teleport.dm

@@ -142,12 +142,12 @@
 		// Can most things breathe?
 		if(trace_gases)
 			continue
-		var/oxy_moles = A.get_moles(/datum/gas/oxygen)
+		var/oxy_moles = A.get_moles(GAS_O2)
 		if(oxy_moles < 16 || oxy_moles > 50)
 			continue
-		if(A.get_moles(/datum/gas/plasma))
+		if(A.get_moles(GAS_PLASMA))
 			continue
-		if(A.get_moles(/datum/gas/carbon_dioxide) >= 10)
+		if(A.get_moles(GAS_CO2) >= 10)
 			continue
 
 		// Aim for goldilocks temperatures and pressure

code/datums/mutations/actions.dm

@@ -227,7 +227,7 @@
 	//can we sniff? is there miasma in the air?
 	var/datum/gas_mixture/air = user.loc.return_air()
 
-	if(air.get_moles(/datum/gas/miasma))
+	if(air.get_moles(GAS_MIASMA))
 		user.adjust_disgust(sensitivity * 45)
 		to_chat(user, "<span class='warning'>With your overly sensitive nose, you get a whiff of stench and feel sick! Try moving to a cleaner area!</span>")
 		return