testament: error instead of silently ignore invalid targets; remove pointless alias target vs targets; document matrix; DRY (#16343)

* testament: error instead of silently ignore invalid targets
* s/target/targets/
* fix test; refs #16344
* address comments
* Update testament/specs.nim

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>

tests/align/talign.nim

@@ -1,6 +1,6 @@
 discard """
 ccodeCheck: "\\i @'NIM_ALIGN(128) NI mylocal1' .*"
-target: "c cpp"
+targets: "c cpp"
 output: "align ok"
 """
 

tests/arc/trtree.nim

@@ -1,7 +1,7 @@
 discard """
   output: '''1 [2, 3, 4, 7]
 [0, 0]'''
-  target: "c"
+  targets: "c"
   joinable: false
 disabled: 32bit
   cmd: "nim c --gc:arc $file"

tests/ccgbugs/tmissingvolatile.nim

@@ -2,7 +2,7 @@ discard """
   output: "1"
   cmd: r"nim c --hints:on $options -d:release $file"
   ccodecheck: "'NI volatile state;'"
-  target: "C"
+  targets: "c"
 """
 
 # bug #1539

tests/ccgbugs/tprogmem.nim

@@ -2,7 +2,7 @@ discard """
   output: "5"
   cmd: r"nim c --hints:on $options -d:release $file"
   ccodecheck: "'/*PROGMEM*/ myLetVariable = {'"
-  target: "C"
+  targets: "c"
 """
 
 var myLetVariable {.exportc, codegenDecl: "$# /*PROGMEM*/ $#".} = [1, 2, 3]

tests/ccgbugs2/tinefficient_const_table.nim

@@ -6,7 +6,7 @@ of
 words'''
   cmd: r"nim c --hints:on $options -d:release $file"
   ccodecheck: "! @'genericSeqAssign'"
-  target: "c"
+  targets: "c"
 """
 
 # bug #4354

tests/closure/tclosure.nim

@@ -1,5 +1,5 @@
 discard """
-  target: "c"
+  targets: "c"
   output: '''
 1 3 6 11 20 foo
 foo88

tests/compiler/tcppCompileToNamespace.nim

@@ -1,6 +1,5 @@
 discard """
 cmd: "nim cpp --cppCompileToNamespace:foo $options -r $file"
-target: cpp
 """
 
 # Theoretically nim could just ignore the flag cppCompileToNamespace

tests/coroutines/texceptions.nim

@@ -1,5 +1,5 @@
 discard """
-  target: "c"
+  targets: "c"
   disabled: true
 """
 

tests/coroutines/tgc.nim

@@ -1,5 +1,5 @@
 discard """
-  target: "c"
+  targets: "c"
 """
 
 import coro

tests/coroutines/titerators.nim

@@ -1,5 +1,5 @@
 discard """
-  target: "c"
+  targets: "c"
 disabled: true
 """
 

tests/coroutines/twait.nim

@@ -1,6 +1,6 @@
 discard """
   output: "Exit 1\nExit 2"
-  target: "c"
+  targets: "c"
 """
 import coro
 

tests/cpp/tevalorder.nim

@@ -2,7 +2,7 @@ discard """
   output: '''0
 1
 2'''
-target: "cpp"
+targets: "cpp"
 """
 
 # bug #8202

tests/destructor/tmove_objconstr.nim

@@ -8,7 +8,7 @@ test destroyed 0
 4
 Pony is dying!'''
 joinable: false
-target: "C"
+targets: "c"
 """
 
 # bug #4214

tests/destructor/tuse_result_prevents_sinks.nim

@@ -1,6 +1,6 @@
 discard """
   output: ""
-  target: "C"
+  targets: "c"
 """
 
 # bug #9594

tests/exception/t9657.nim

@@ -1,7 +1,7 @@
 discard """
   action: run
   exitcode: 1
-  target: "c cpp"
+  targets: "c cpp"
   disabled: "openbsd"
   disabled: "netbsd"
 """

tests/flags/tgenscript.nim

@@ -1,5 +1,5 @@
 discard """
-  target: "c"
+  targets: "c"
   action: compile
 """
 

tests/iter/titervaropenarray.nim

@@ -1,6 +1,6 @@
 discard """
   output: "123"
-  targets: "C"
+  targets: "c"
 """
 # Try to break the transformation pass:
 iterator iterAndZero(a: var openArray[int]): int =

tests/objects/tobjcov.nim

@@ -1,6 +1,6 @@
 discard """
 action: compile
-target: "c"
+targets: "c"
 """
 
 # Covariance is not type safe:

tests/stdlib/t10231.nim

@@ -1,5 +1,5 @@
 discard """
-  target: cpp
+  targets: "cpp"
   action: run
   exitcode: 0
 """

tests/stdlib/thashes.nim

@@ -1,5 +1,5 @@
 discard """
-  targets: '''c c++ js'''
+  targets: "c cpp js"
 """
 
 import hashes

tests/stdlib/ttimes.nim

@@ -1,5 +1,5 @@
 discard """
-  target: "c js"
+  targets: "c js"
 """
 
 import times, strutils, unittest

tests/system/tatomics1.nim

@@ -1,5 +1,5 @@
 discard """
-  target: "c cpp js"
+  targets: "c cpp js"
 """
 
 var x = 10