Same-line shellcheck comment explanations

These are obvious even with `git grep shellcheck`.

test/asm/test.sh

@@ -11,8 +11,7 @@ input="$(mktemp)"
 output="$(mktemp)"
 errput="$(mktemp)"
 
-# Immediate expansion is the desired behavior.
-# shellcheck disable=SC2064
+# shellcheck disable=SC2064 # (Immediate expansion is the desired behavior.)
 trap "rm -f ${o@Q} ${gb@Q} ${input@Q} ${output@Q} ${errput@Q}" EXIT
 
 tests=0
@@ -91,11 +90,7 @@ for i in *.asm notexist.asm; do
 				continue
 			fi
 
-			# Stop! This is not a Useless Use Of Cat. Using cat instead of
-			# stdin redirection makes the input an unseekable pipe - a scenario
-			# that's harder to deal with and was broken when the feature was
-			# first implemented.
-			# shellcheck disable=SC2002
+			# shellcheck disable=SC2002 # (This use of `cat` intentionally makes the input an unseekable pipe.)
 			cat "$i" | "$RGBASM" "${RGBASMFLAGS[@]}" -o "$o" - >"$output" 2>"$errput"
 
 			# Use two otherwise unused files for temp storage
@@ -230,7 +225,7 @@ for variant in '' '.pipe'; do
 	if [ -z "$variant" ]; then
 		"$RGBASM" "${RGBASMFLAGS[@]}" -s "$state_features:$state_outname" "$i"/a.asm >"$output" 2>"$errput"
 	else
-		# shellcheck disable=SC2002
+		# shellcheck disable=SC2002 # (This use of `cat` intentionally makes the input an unseekable pipe.)
 		cat "$i"/a.asm | "$RGBASM" "${RGBASMFLAGS[@]}" -s "$state_features:$state_outname" - >"$output" 2>"$errput"
 	fi
 

test/fix/test.sh

@@ -3,8 +3,7 @@
 export LC_ALL=C
 
 tmpdir="$(mktemp -d)"
-# Immediate expansion is the desired behavior.
-# shellcheck disable=SC2064
+# shellcheck disable=SC2064 # (Immediate expansion is the desired behavior.)
 trap "cd; rm -rf ${tmpdir@Q}" EXIT
 
 src="$PWD"
@@ -73,10 +72,7 @@ runTest () {
 			eval "$RGBFIX" $flags out.gb '>out.out' '2>out.err'
 			subst=out.gb
 		elif [[ "$variant" = ' piped' ]]; then
-			# Stop! This is not a Useless Use Of Cat. Using cat instead of
-			# stdin redirection makes the input an unseekable pipe - a scenario
-			# that's harder to deal with.
-			# shellcheck disable=SC2002
+			# shellcheck disable=SC2002 # (This use of `cat` intentionally makes the input an unseekable pipe.)
 			cat "$desired_input" | eval "$RGBFIX" $flags - '>out.gb' '2>out.err'
 			subst='<stdin>'
 		elif [[ "$variant" = ' output' ]]; then

test/gfx/test.sh

@@ -5,8 +5,7 @@
 
 errtmp="$(mktemp)"
 
-# Immediate expansion is the desired behavior.
-# shellcheck disable=SC2064
+# shellcheck disable=SC2064 # (Immediate expansion is the desired behavior.)
 trap "rm -f ${errtmp@Q} result.{png,1bpp,2bpp,pal,tilemap,attrmap,palmap} out*.png" EXIT
 
 tests=0

test/link/test.sh

@@ -10,8 +10,7 @@ outtemp="$(mktemp)"
 outtemp2="$(mktemp)"
 outtemp3="$(mktemp)"
 
-# Immediate expansion is the desired behavior.
-# shellcheck disable=SC2064
+# shellcheck disable=SC2064 # (Immediate expansion is the desired behavior.)
 trap "rm -f ${otemp@Q} ${gbtemp@Q} ${gbtemp2@Q} ${outtemp@Q} ${outtemp2@Q} ${outtemp3@Q}" EXIT
 
 tests=0