/usr/share/intel2gas/i2g/num.syntax is in intel2gas 1.3.3-16+b2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | # this simply converts the NASM number format to AT&T style
# the hex,oct,dec,bin all only match the numbers they indicate
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<bin>b
0b<bin>
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0<hex>h
0x<hex>
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$0<hex>
0x<hex>
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0x<hex>
0x<hex>
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<hex>h
0x<hex>
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<dec>
<dec>
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