deprecate newruntime (#17245)

* deprecate newruntime
* tests
* Update compiler/commands.nim

tests/destructor/t12037.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: '''nim c --newruntime $file'''
+  cmd: '''nim c --gc:arc $file'''
   output: '''
 showing original type, length, and contents seq[int] 1 @[42]
 copy length and contents 1 @[42]

tests/destructor/tarray_indexing.nim

@@ -1,7 +1,7 @@
 discard """
   output: '''allocating 1048576 65536
 filling page from 1048576 len 65536'''
-  cmd: '''nim c --newruntime $file'''
+  cmd: '''nim c --gc:arc $file'''
 """
 
 # bug #12669

tests/destructor/tcaseobj_transitions.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: '''nim c --newruntime $file'''
+  cmd: '''nim c --gc:arc $file'''
   output: '''no crash'''
 """
 

tests/destructor/tgcdestructors.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: '''nim c -d:nimAllocStats --newruntime $file'''
+  cmd: '''nim c -d:nimAllocStats --gc:arc $file'''
   output: '''hi
 ho
 ha

tests/destructor/tglobaldestructor.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: '''nim c --newruntime $file'''
+  cmd: '''nim c --gc:arc $file'''
   output: '''(v: 42)
 igotdestroyed'''
 """

tests/destructor/tnewruntime_strutils.nim

@@ -1,6 +1,6 @@
 discard """
   valgrind: true
-  cmd: '''nim c -d:nimAllocStats --newruntime -d:useMalloc $file'''
+  cmd: '''nim c -d:nimAllocStats --gc:arc -d:useMalloc $file'''
   output: '''
 @[(input: @["KXSC", "BGMC"]), (input: @["PXFX"]), (input: @["WXRQ", "ZSCZD"])]
 14

tests/destructor/towned_binary_tree.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: '''nim c -d:nimAllocStats --newruntime $file'''
+  cmd: '''nim c -d:nimAllocStats --gc:arc $file'''
   output: '''31665
 (allocCount: 33334, deallocCount: 33334)'''
 """

tests/destructor/tsimpleclosure.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: '''nim c -d:nimAllocStats --newruntime $file'''
+  cmd: '''nim c -d:nimAllocStats --gc:arc $file'''
   output: '''a b
 70
 hello

tests/destructor/tv2_cast.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: '''nim c --newruntime $file'''
+  cmd: '''nim c --gc:arc $file'''
   output: '''@[1]
 @[116, 101, 115, 116]
 @[1953719668, 875770417]'''