test prerequisites: eradicate NOT_FOO

Support for Back when bdccd3c1 (test-lib: allow negation of
prerequisites, 2012-11-14) introduced negated predicates
(e.g. "!MINGW,!CYGWIN"), we already had 5 test files that use
NOT_MINGW (and a few MINGW) as prerequisites.

Let's not add NOT_FOO and rewrite existing ones as !FOO for both
MINGW and CYGWIN.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t1402-check-ref-format.sh b/t/t1402-check-ref-format.sh
index 9aeb352..28e9318 100755
--- a/t/t1402-check-ref-format.sh
+++ b/t/t1402-check-ref-format.sh
@@ -7,7 +7,7 @@
 valid_ref() {
 	prereq=
 	case $1 in
-	[A-Z]*)
+	[A-Z!]*)
 		prereq=$1
 		shift
 	esac
@@ -19,7 +19,7 @@
 invalid_ref() {
 	prereq=
 	case $1 in
-	[A-Z]*)
+	[A-Z!]*)
 		prereq=$1
 		shift
 	esac
@@ -30,17 +30,17 @@
 }
 
 invalid_ref ''
-invalid_ref NOT_MINGW '/'
-invalid_ref NOT_MINGW '/' --allow-onelevel
-invalid_ref NOT_MINGW '/' --normalize
-invalid_ref NOT_MINGW '/' '--allow-onelevel --normalize'
+invalid_ref !MINGW '/'
+invalid_ref !MINGW '/' --allow-onelevel
+invalid_ref !MINGW '/' --normalize
+invalid_ref !MINGW '/' '--allow-onelevel --normalize'
 valid_ref 'foo/bar/baz'
 valid_ref 'foo/bar/baz' --normalize
 invalid_ref 'refs///heads/foo'
 valid_ref 'refs///heads/foo' --normalize
 invalid_ref 'heads/foo/'
-invalid_ref NOT_MINGW '/heads/foo'
-valid_ref NOT_MINGW '/heads/foo' --normalize
+invalid_ref !MINGW '/heads/foo'
+valid_ref !MINGW '/heads/foo' --normalize
 invalid_ref '///heads/foo'
 valid_ref '///heads/foo' --normalize
 invalid_ref './foo'
@@ -120,14 +120,14 @@
 invalid_ref "$ref" '--refspec-pattern --allow-onelevel'
 
 ref='/foo'
-invalid_ref NOT_MINGW "$ref"
-invalid_ref NOT_MINGW "$ref" --allow-onelevel
-invalid_ref NOT_MINGW "$ref" --refspec-pattern
-invalid_ref NOT_MINGW "$ref" '--refspec-pattern --allow-onelevel'
-invalid_ref NOT_MINGW "$ref" --normalize
-valid_ref NOT_MINGW "$ref" '--allow-onelevel --normalize'
-invalid_ref NOT_MINGW "$ref" '--refspec-pattern --normalize'
-valid_ref NOT_MINGW "$ref" '--refspec-pattern --allow-onelevel --normalize'
+invalid_ref !MINGW "$ref"
+invalid_ref !MINGW "$ref" --allow-onelevel
+invalid_ref !MINGW "$ref" --refspec-pattern
+invalid_ref !MINGW "$ref" '--refspec-pattern --allow-onelevel'
+invalid_ref !MINGW "$ref" --normalize
+valid_ref !MINGW "$ref" '--allow-onelevel --normalize'
+invalid_ref !MINGW "$ref" '--refspec-pattern --normalize'
+valid_ref !MINGW "$ref" '--refspec-pattern --allow-onelevel --normalize'
 
 
 valid_ref 'refs/heads/a-very-long-refname'
@@ -176,7 +176,7 @@
 valid_ref_normalized() {
 	prereq=
 	case $1 in
-	[A-Z]*)
+	[A-Z!]*)
 		prereq=$1
 		shift
 	esac
@@ -188,7 +188,7 @@
 invalid_ref_normalized() {
 	prereq=
 	case $1 in
-	[A-Z]*)
+	[A-Z!]*)
 		prereq=$1
 		shift
 	esac
@@ -199,10 +199,10 @@
 
 valid_ref_normalized 'heads/foo' 'heads/foo'
 valid_ref_normalized 'refs///heads/foo' 'refs/heads/foo'
-valid_ref_normalized NOT_MINGW '/heads/foo' 'heads/foo'
+valid_ref_normalized !MINGW '/heads/foo' 'heads/foo'
 valid_ref_normalized '///heads/foo' 'heads/foo'
 invalid_ref_normalized 'foo'
-invalid_ref_normalized NOT_MINGW '/foo'
+invalid_ref_normalized !MINGW '/foo'
 invalid_ref_normalized 'heads/foo/../bar'
 invalid_ref_normalized 'heads/./foo'
 invalid_ref_normalized 'heads\foo'