Optimize runtime attributes at very low priority

This is such that the version of the runtime would
not influence whether we should reuse a spec.

Compiler mismatches are considered for runtimes,
to avoid situations where compiling foo%gcc@9
brings in gcc-runtime%gcc@13 if gcc@13 is among
the available compilers

lib/spack/spack/solver/concretize.lp

@@ -1486,18 +1486,20 @@ opt_criterion(40, "compiler mismatches that are not from CLI").
 #minimize{ 0@240: #true }.
 #minimize{ 0@40: #true }.
 #minimize{
-    1@40+Priority,PackageNode,DependencyNode
-    : compiler_mismatch(PackageNode, DependencyNode),
-      build_priority(DependencyNode, Priority)
+    1@40+Priority,PackageNode,node(ID, Dependency)
+    : compiler_mismatch(PackageNode, node(ID, Dependency)),
+      build_priority(node(ID, Dependency), Priority),
+      not runtime(Dependency)
 }.
 
 opt_criterion(39, "compiler mismatches that are not from CLI").
 #minimize{ 0@239: #true }.
 #minimize{ 0@39: #true }.
 #minimize{
-    1@39+Priority,PackageNode,DependencyNode
-    : compiler_mismatch_required(PackageNode, DependencyNode),
-      build_priority(DependencyNode, Priority)
+    1@39+Priority,PackageNode,node(ID, Dependency)
+    : compiler_mismatch_required(PackageNode, node(ID, Dependency)),
+      build_priority(node(ID, Dependency), Priority),
+      not runtime(Dependency)
 }.
 
 opt_criterion(30, "non-preferred OS's").
@@ -1536,9 +1538,10 @@ opt_criterion(15, "non-preferred compilers").
 #minimize{ 0@215: #true }.
 #minimize{ 0@15: #true }.
 #minimize{
-    Weight@15+Priority,PackageNode
-    : node_compiler_weight(PackageNode, Weight),
-      build_priority(PackageNode, Priority)
+    Weight@15+Priority,node(X, Package)
+    : node_compiler_weight(node(X, Package), Weight),
+      build_priority(node(X, Package), Priority),
+      not runtime(Package)
 }.
 
 % Minimize the number of mismatches for targets in the DAG, try
@@ -1547,27 +1550,54 @@ opt_criterion(10, "target mismatches").
 #minimize{ 0@210: #true }.
 #minimize{ 0@10: #true }.
 #minimize{
-    1@10+Priority,PackageNode,DependencyNode
-    : node_target_mismatch(PackageNode, DependencyNode),
-      build_priority(DependencyNode, Priority)
+    1@10+Priority,PackageNode,node(ID, Dependency)
+    : node_target_mismatch(PackageNode, node(ID, Dependency)),
+      build_priority(node(ID, Dependency), Priority),
+      not runtime(Dependency)
 }.
 
 opt_criterion(5, "non-preferred targets").
 #minimize{ 0@205: #true }.
 #minimize{ 0@5: #true }.
 #minimize{
-    Weight@5+Priority,PackageNode
-    : node_target_weight(PackageNode, Weight),
-      build_priority(PackageNode, Priority)
+    Weight@5+Priority,node(X, Package)
+    : node_target_weight(node(X, Package), Weight),
+      build_priority(node(X, Package), Priority),
+      not runtime(Package)
 }.
 
+
+% Minimize the number of compiler mismatches for runtimes
+opt_criterion(4, "compiler mismatches (runtimes)").
+#minimize{ 0@204: #true }.
+#minimize{ 0@4: #true }.
+#minimize{
+    1@4,PackageNode,node(ID, Dependency)
+    : compiler_mismatch(PackageNode, node(ID, Dependency)), runtime(Dependency)
+}.
+#minimize{
+    1@4,PackageNode,node(ID, Dependency)
+    : compiler_mismatch_required(PackageNode, node(ID, Dependency)), runtime(Dependency)
+}.
+
+
 % Choose more recent versions for runtimes
-opt_criterion(2, "version badness (runtimes)").
+opt_criterion(3, "version badness (runtimes)").
+#minimize{ 0@203: #true }.
+#minimize{ 0@3: #true }.
+#minimize{
+    Weight@3,node(X, Package)
+    : version_weight(node(X, Package), Weight),
+      runtime(Package)
+}.
+
+% Choose best target for runtimes
+opt_criterion(2, "non-preferred targets (runtimes)").
 #minimize{ 0@202: #true }.
 #minimize{ 0@2: #true }.
 #minimize{
     Weight@2,node(X, Package)
-    : version_weight(node(X, Package), Weight),
+    : node_target_weight(node(X, Package), Weight),
       runtime(Package)
 }.