gsl/2.{6,7}: built for current GCC versions, migrate to YAML format

Compiler/gsl/files/variants.rhel6

@@ -1,17 +0,0 @@
-gsl/1.15	stable		gcc/{4.7.4,4.8.3,4.8.4,4.8.5,4.9.3,4.9.4}
-gsl/1.15	deprecated	gcc/4.9.2 
-gsl/1.15	stable		gcc/{5.3.0,5.4.0,6.2.0}
-
-gsl/1.16	stable		gcc/{4.8.5,4.9.4,5.4.0,6.2.0} 
-gsl/2.2.1       stable		gcc/{4.8.5,4.9.4,5.4.0,6.2.0,6.3.0} 
-
-gsl/2.4		stable		gcc/7.3.0 
-gsl/2.4		deprecated	intel/17.4
-
-gsl/2.5		stable		gcc/{6.3.0,7.3.0,7.4.0,8.3.0,9.1.0} 
-gsl/2.5		deprecated	intel/19.4 
-
-gsl/2.6		stable		gcc/{7.4.0,7.5.0,8.3.0,8.4.0,9.2.0,9.3.0,10.1.0,10.2.0,10.3.0}
-
-gsl/2.7		stable		gcc/{7.5.0,8.4.0,9.3.0,10.3.0}
-

Compiler/gsl/files/variants.yaml

@@ -0,0 +1,37 @@
+gsl/1.15:
+  - with: gcc/{4.7.4,4.8.3,4.8.4,4.8.5,4.9.2,4.9.3,4.9.4,5.3.0,5.4.0,6.2.0}
+    relstage: deprecated
+gsl/1.15:
+  - with: intel/15.3
+    relstage: deprecated
+
+gsl/1.16:
+  - with: gcc/{4.8.5,4.9.4,5.4.0,6.2.0}
+    relstage: deprecated
+
+gsl/2.2.1:
+  - with: gcc/{4.8.5,4.9.4,5.4.0,6.2.0,6.3.0} 
+    relstage: deprecated
+
+gsl/2.4:
+  - with: gcc/7.3.0 
+    relstage: deprecated
+gsl/2.4:
+  - with: intel/17.4
+    relstage: deprecated
+
+gsl/2.5:
+  - with: gcc/{6.3.0,7.3.0,7.4.0,8.3.0,9.1.0} 
+    relstage: deprecated
+gsl/2.5:
+  - with: intel/19.4 
+    relstage: deprecated
+
+gsl/2.6:
+  - with: gcc/{7.4.0,7.5.0,8.3.0,8.4.0,8.5.0,9.2.0,9.3.0,9.5.0,10.1.0,10.2.0,10.3.0,11.2.0,12.1.0}
+    relstage: stable
+
+gsl/2.7:
+  - with: gcc/{7.5.0,8.5.0,9.5.0,10.3.0,11.3.0,12.1.0}
+    relstage: stable
+