Add unit tests for part of base library plus fixes to [gs]etfenv, [gs]etmetatable

src/test/res/setfenv.lua

@@ -0,0 +1,40 @@
+-- unit tests for getfenv, setfenv
+local function f3(level,value)
+	if value then
+		setfenv( level, {setfenv=setfenv, abc=value} )
+	end
+	return abc         
+end
+local function f2(...)
+	local r = f3(...)
+	return abc,r 
+end
+local function f1(...)
+	local r,s = f2(...)
+	return abc,r,s
+end
+print( 'getfenv,setfenv - before')
+print( 'getfenv(f1)["abc"]', getfenv(f1)["abc"] ) 
+print( 'getfenv(f2)["abc"]', getfenv(f2)["abc"] ) 
+print( 'getfenv(f3)["abc"]', getfenv(f3)["abc"] ) 
+print( 'getfenv()["abc"]', getfenv()["abc"] ) 
+print( 'abc,f1()', abc,f1() )
+setfenv(f1,{setfenv=setfenv, abc='ghi'})
+setfenv(f2,{setfenv=setfenv, abc='jkl'})
+setfenv(f3,{setfenv=setfenv, abc='mno'})
+print( 'getfenv,setfenv - after')
+print( 'getfenv(f1)["abc"]', getfenv(f1)["abc"] ) 
+print( 'getfenv(f2)["abc"]', getfenv(f2)["abc"] ) 
+print( 'getfenv(f3)["abc"]', getfenv(f3)["abc"] ) 
+print( 'getfenv()["abc"]', getfenv()["abc"] ) 
+print( 'abc,f1()', abc,f1() )
+print( 'abc,f1(1,"pqr")', abc,f1(1,"pqr") )
+print( 'abc,f1(2,"stu")', abc,f1(2,"stu") )
+print( 'abc,f1(3,"vwx")', abc,f1(3,"vwx") )
+print( 'abc', abc )
+local c = coroutine.create( function()
+	print( 'pcall(f1,0,"abc")', pcall(f1,0,"234") )
+end )
+print( 'resume', coroutine.resume(c) )
+print( 'abc,pcall(f1)', abc,pcall(f1) )
+print( 'abc (out)', abc )