use targets from test spec when running testament tests (#6687)

tests/cpp/tasync_cpp.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
   output: "hello"
 """
 

tests/cpp/tcovariancerules.nim

@@ -1,5 +1,5 @@
 discard """
-cmd: "nim cpp $file"
+targets: "cpp"
 output: '''
 cat
 cat

tests/cpp/tcppraise.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
   output: '''foo
 bar
 Need odd and >= 3 digits##

tests/cpp/tdont_init_instantiation.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
   output: ''''''
   disabled: true
 """

tests/cpp/tembarrassing_generic_failure.nim

@@ -1,4 +1,5 @@
 discard """
+  targets: "cpp"
   cmd: "nim cpp --threads:on $file"
 """
 

tests/cpp/temitlist.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
   output: '''6.0'''
 """
 

tests/cpp/tempty_generic_obj.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
   output: '''int
 float'''
 """

tests/cpp/tgen_prototype_for_importc.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
   output: '''Hello world'''
 """
 

tests/cpp/tget_subsystem.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
 """
 
 {.emit: """

tests/cpp/tnativesockets.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
 """
 
 import nativesockets

tests/cpp/treturn_array.nim

@@ -1,3 +1,6 @@
+discard """
+  targets: "cpp"
+"""
 
 # bug #2259
 type Mat4f* = array[0..15, float]

tests/cpp/tsigbreak.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
 """
 
 import tables, lists

tests/cpp/tstaticvar_via_typedesc.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
   output: "42"
 """
 

tests/cpp/ttemplatetype.nim

@@ -1,3 +1,7 @@
+discard """
+  targets: "cpp"
+"""
+
 type
   Map {.importcpp: "std::map", header: "<map>".} [T,U] = object
 

tests/cpp/tthread_createthread.nim

@@ -1,4 +1,5 @@
 discard """
+  targets: "cpp"
   cmd: "nim cpp --hints:on --threads:on $options $file"
 """
 

tests/cpp/ttypeinfo.nim

@@ -1,6 +1,6 @@
 discard """
+  targets: "cpp"
   output: '''100'''
-  cmd: "nim cpp $file"
 """
 
 import typeinfo

tests/cpp/ttypeinfo2.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
 """
 # bug #2841
 import typeinfo

tests/cpp/tvector_iterator.nim

@@ -1,5 +1,5 @@
 discard """
-  cmd: "nim cpp $file"
+  targets: "cpp"
 """
 
 {.emit: """

tests/cpp/tvectorseq.nim

@@ -1,7 +1,7 @@
 discard """
+  targets: "cpp"
   output: '''(x: 1.0)
 (x: 0.0)'''
-  cmd: "nim cpp $file"
   disabled: "true"
 """