unicode: document large var blocks and the SpecialCase vars.

Fixes #2772.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5631047

src/pkg/unicode/casetables.go

@@ -9,7 +9,7 @@
 
 package unicode
 
-var TurkishCase = _TurkishCase
+var TurkishCase SpecialCase = _TurkishCase
 var _TurkishCase = SpecialCase{
 	CaseRange{0x0049, 0x0049, d{0, 0x131 - 0x49, 0}},
 	CaseRange{0x0069, 0x0069, d{0x130 - 0x69, 0, 0x130 - 0x69}},
@@ -17,4 +17,4 @@ var _TurkishCase = SpecialCase{
 	CaseRange{0x0131, 0x0131, d{0x49 - 0x131, 0, 0x49 - 0x131}},
 }
 
-var AzeriCase = _TurkishCase
+var AzeriCase SpecialCase = _TurkishCase

src/pkg/unicode/maketables.go

@@ -486,6 +486,7 @@ func printCategories() {
 			func(code rune) bool { return chars[code].category == name })
 	}
 	decl.Sort()
+	fmt.Println("// The following variables are of type *RangeTable:")
 	fmt.Println("var (")
 	for _, d := range decl {
 		fmt.Print(d)
@@ -768,6 +769,7 @@ func printScriptOrProperty(doProps bool) {
 		fmt.Print("}\n\n")
 	}
 	decl.Sort()
+	fmt.Println("// The following variables are of type *RangeTable:")
 	fmt.Println("var (")
 	for _, d := range decl {
 		fmt.Print(d)

src/pkg/unicode/tables.go

@@ -2701,6 +2701,7 @@ var _Zs = &RangeTable{
 	},
 }
 
+// The following variables are of type *RangeTable:
 var (
 	Cc     = _Cc // Cc is the set of Unicode characters in category Cc.
 	Cf     = _Cf // Cf is the set of Unicode characters in category Cf.
@@ -4053,6 +4054,7 @@ var _Yi = &RangeTable{
 	},
 }
 
+// The following variables are of type *RangeTable:
 var (
 	Arabic                 = _Arabic                 // Arabic is the set of Unicode characters in script Arabic.
 	Armenian               = _Armenian               // Armenian is the set of Unicode characters in script Armenian.
@@ -5114,6 +5116,7 @@ var _White_Space = &RangeTable{
 	},
 }
 
+// The following variables are of type *RangeTable:
 var (
 	ASCII_Hex_Digit                    = _ASCII_Hex_Digit                    // ASCII_Hex_Digit is the set of Unicode characters with property ASCII_Hex_Digit.
 	Bidi_Control                       = _Bidi_Control                       // Bidi_Control is the set of Unicode characters with property Bidi_Control.