[use] Remove workaround for reserved code points

See <https://github.com/microsoft/font-tools/issues/12>.

src/gen-use-table.py

diff --git a/src/gen-use-table.py b/src/gen-use-table.py
index 608ae2a..a1865e9 100755
--- a/src/gen-use-table.py
+++ b/src/gen-use-table.py
@@ -241,9 +241,7 @@
 	return (UISC in [Number, Consonant, Consonant_Head_Letter,
 			Tone_Letter,
 			Vowel_Independent,
-			] and
-			# TODO: https://github.com/microsoft/font-tools/issues/12
-			UGC != Cn or
+			] or
 		# TODO: https://github.com/MicrosoftDocs/typography-issues/issues/484
 		AJT in [jt_C, jt_D, jt_L, jt_R] and UISC != Joiner or
 		(UGC == Lo and UISC in [Avagraha, Bindu, Consonant_Final, Consonant_Medial,

src/ms-use/IndicSyllabicCategory-Additional.txt

diff --git a/src/ms-use/IndicSyllabicCategory-Additional.txt b/src/ms-use/IndicSyllabicCategory-Additional.txt
index 5624166..969fa92 100644
--- a/src/ms-use/IndicSyllabicCategory-Additional.txt
+++ b/src/ms-use/IndicSyllabicCategory-Additional.txt
@@ -96,7 +96,10 @@
 16F00..16F4A ; Consonant # Lo   [75] MIAO LETTER PA..MIAO LETTER RTE
 16FE4        ; Consonant # Mn        KHITAN SMALL SCRIPT FILLER
 18B00..18CD5 ; Consonant # Lo  [470] KHITAN SMALL SCRIPT CHARACTER-18B00..KHITAN SMALL SCRIPT CHARACTER-18CD5
-1BC00..1BC99 ; Consonant # Lo  [139] DUPLOYAN LETTER H..DUPLOYAN AFFIX LOW ARROW
+1BC00..1BC6A ; Consonant # Lo  [107] DUPLOYAN LETTER H..DUPLOYAN LETTER VOCALIC M
+1BC70..1BC7C ; Consonant # Lo   [13] DUPLOYAN AFFIX LEFT HORIZONTAL SECANT..DUPLOYAN AFFIX ATTACHED TANGENT HOOK 
+1BC80..1BC88 ; Consonant # Lo    [9] DUPLOYAN AFFIX HIGH ACUTE..DUPLOYAN AFFIX HIGH VERTICAL
+1BC90..1BC99 ; Consonant # Lo   [10] DUPLOYAN AFFIX LOW ACUTE..DUPLOYAN AFFIX LOW ARROW
 1E100..1E12C ; Consonant # Lo   [45] NYIAKENG PUACHUE HMONG LETTER MA..NYIAKENG PUACHUE HMONG LETTER W
 1E137..1E13D ; Consonant # Lm    [7] NYIAKENG PUACHUE HMONG SIGN FOR PERSON..NYIAKENG PUACHUE HMONG SYLLABLE LENGTHENER
 1E14E        ; Consonant # Lo        NYIAKENG PUACHUE HMONG LOGOGRAM NYAJ