Fix OOM for too-small overlay files in 32K mode (rgblink -t)

test/link/overlay/smaller-32k/a.asm

@@ -0,0 +1,2 @@
+SECTION "test", ROM0[$42]
+Label:: dw Label

test/link/overlay/smaller-32k/out.err

@@ -0,0 +1,3 @@
+warning: Overlay file does not have a size multiple of 0x4000
+warning: Overlay is less than 0x8000 bytes large
+warning: Output is larger than overlay file, but no padding value was specified

test/link/overlay/smaller/out.err

@@ -1 +1,2 @@
 warning: Overlay file does not have a size multiple of 0x4000
+warning: Overlay is less than 0x8000 bytes large

test/link/test.sh

@@ -260,6 +260,16 @@ tryDiff "$test"/out.err "$outtemp"
 tryCmp "$test"/out.gb "$gbtemp"
 evaluateTest
 
+test="overlay/smaller-32k"
+startTest
+"$RGBASM" -o "$otemp" "$test"/a.asm
+continueTest
+rgblinkQuiet -o "$gbtemp" -t -O "$test"/overlay.gb "$otemp" 2>"$outtemp"
+tryDiff "$test"/out.err "$outtemp"
+# This test does not trim its output with 'dd' because it needs to verify the correct output size
+tryCmp "$test"/out.gb "$gbtemp"
+evaluateTest
+
 test="overlay/unfixed"
 startTest
 "$RGBASM" -o "$otemp" "$test"/a.asm