exp/locale/collate/tools/colcmp: fixes some discrepancies between

ICU and collate package: ICU requires strings to be in FCD form.
Not all NFC strings are in this form, leading to incorrect results.
Change to NFD instead.

R=rsc
CC=golang-dev
https://golang.org/cl/7201043

src/pkg/exp/locale/collate/tools/colcmp/colcmp.go

@@ -279,7 +279,7 @@ func parseInput(args []string) []Input {
 		}
 		s = string(rs)
 		if *doNorm {
-			s = norm.NFC.String(s)
+			s = norm.NFD.String(s)
 		}
 		input = append(input, makeInputString(s))
 	}

src/pkg/exp/locale/collate/tools/colcmp/gen.go

@@ -139,7 +139,7 @@ func (g *phraseGenerator) generate(doNorm bool) []Input {
 			buf16 = make([]uint16, 0, buf16Size)
 		}
 		if doNorm {
-			buf8 = norm.NFC.AppendString(buf8, str)
+			buf8 = norm.NFD.AppendString(buf8, str)
 		} else {
 			buf8 = append(buf8, str...)
 		}