test: add test for preprocessor indirection construct

Add a test for the preprocessor indirection construct, %[...].

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

test/ppindirect.asm

@@ -0,0 +1,39 @@
+;Testname=test; Arguments=-E -o ppindirect.out; Files=ppindirect.out
+
+; Fun tests of the preprocessor indirection mode...
+
+%assign foo1		11
+%assign foo11		1111
+%assign foo2		22
+%assign foo22		2222
+%assign foo3		33
+%assign foo33		3333
+%assign n		2
+foo%[foo%[n]]*100
+foo%[n]*100
+%assign foo%[foo%[n]]	foo%[foo%[n]]*100
+;%assign foo%[n]		foo%[n]*100
+
+	foo1
+	foo2
+	foo3
+	foo11
+	foo22
+	foo33
+
+%assign bctr 0
+%macro bluttan 0
+%assign bctr bctr+1
+%assign bluttan%[bctr]	bctr
+%defstr bstr bluttan%[bctr]
+	bluttan%[bctr]
+	bstr
+%endmacro
+
+%rep 20
+	bluttan
+%endrep
+%rep 20
+	bluttan%[bctr]
+%assign bctr bctr-1
+%endrep