Switch from parentheses to angle brackets

`\(` is more likely to be a valid escape sequence in the
future (as is `\[`) and `\{` is already taken.

test/asm/bracketed-macro-args.asm

@@ -0,0 +1,19 @@
+MACRO printargs
+	PRINTLN "first = \<1>"
+	FOR I, 2, _NARG
+		PRINTLN "next = \<{d:I}>"
+	ENDR
+	PRINTLN "last = \<{d:_NARG}>"
+ENDM
+
+	printargs A, B, C, D
+
+MACRO mac
+	println \<2__> + \<1_2> + \<\1>
+x = 2
+	println \<{d:x}> + \<1_{d:x}> + \<\<\<13>>>
+y equs "NARG"
+	println \<x> + \<1_{d:x}_> + \<\<\<_{y}>>>
+ENDM
+
+	mac 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 1

test/asm/invalid-empty-macro-arg.asm

@@ -1 +1 @@
-\()
+\<>

test/asm/invalid-empty-macro-arg.err

@@ -1,2 +1,2 @@
 FATAL: invalid-empty-macro-arg.asm(1):
-    Empty parenthetic macro argument
+    Empty bracketed macro argument

test/asm/invalid-macro-arg-character.asm

@@ -1 +1 @@
-\(10!)
+\<10!>

test/asm/invalid-macro-arg-character.err

@@ -1,2 +1,2 @@
 FATAL: invalid-macro-arg-character.asm(1):
-    Invalid character in parenthetic macro argument '!'
+    Invalid character in bracketed macro argument '!'

test/asm/invalid-macro-arg-symbol.asm

@@ -1 +1 @@
-\(foo)
+\<foo>

test/asm/invalid-macro-arg-symbol.err

@@ -1,2 +1,2 @@
 FATAL: invalid-macro-arg-symbol.asm(1):
-    Parenthetic symbol "foo" does not exist
+    Bracketed symbol "foo" does not exist

test/asm/parenthetic-macro-args.asm

@@ -1,19 +0,0 @@
-MACRO printargs
-	PRINTLN "first = \(1)"
-	FOR I, 2, _NARG
-		PRINTLN "next = \({d:I})"
-	ENDR
-	PRINTLN "last = \({d:_NARG})"
-ENDM
-
-	printargs A, B, C, D
-
-MACRO mac
-	println \(2__) + \(1_2) + \(\1)
-x = 2
-	println \({d:x}) + \(1_{d:x}) + \(\(\(13)))
-y equs "NARG"
-	println \(x) + \(1_{d:x}_) + \(\(\(_{y})))
-ENDM
-
-	mac 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 1

test/asm/quine.asm

@@ -1,6 +1,6 @@
 MACRO N
 FOR R,1,_NARG+1
-PRINT STRSUB("\n\"\\ PR1NT,ABCDEFGHIMnOSU2_+-()",\(R)+1,1)
+PRINT STRSUB("\n\"\\ PR1NT,ABCDEFGHIMnOSU2_+-()<>",\<R>+1,1)
 ENDR
 REPT R-2
 PRINT"\1,"
@@ -8,4 +8,4 @@ SHIFT
 ENDR
 PRINT"\1\n"
 ENDM
- N 19,10,12,5,21,3,7,0,15,21,5,3,5,9,6,9,25,7,10,5,16,26,6,0,4,5,18,7,8,3,22,8,5,22,23,11,28,1,2,20,2,1,2,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,1,9,2,28,5,29,26,6,9,6,29,0,14,7,13,5,0,5,14,4,8,3,5,27,24,0,4,5,18,7,8,1,2,6,9,1,0,22,17,18,15,8,0,14,7,13,5,0,4,5,18,7,8,1,2,6,2,20,1,0,14,7,13,19,0,3,7,3
+ N 19,10,12,5,21,3,7,0,15,21,5,3,5,9,6,9,25,7,10,5,16,26,6,0,4,5,18,7,8,3,22,8,5,22,23,11,28,1,2,20,2,1,2,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,1,9,2,30,5,31,26,6,9,6,29,0,14,7,13,5,0,5,14,4,8,3,5,27,24,0,4,5,18,7,8,1,2,6,9,1,0,22,17,18,15,8,0,14,7,13,5,0,4,5,18,7,8,1,2,6,2,20,1,0,14,7,13,19,0,3,7,3

test/asm/quine.out

@@ -1,6 +1,6 @@
 MACRO N
 FOR R,1,_NARG+1
-PRINT STRSUB("\n\"\\ PR1NT,ABCDEFGHIMnOSU2_+-()",\(R)+1,1)
+PRINT STRSUB("\n\"\\ PR1NT,ABCDEFGHIMnOSU2_+-()<>",\<R>+1,1)
 ENDR
 REPT R-2
 PRINT"\1,"
@@ -8,4 +8,4 @@ SHIFT
 ENDR
 PRINT"\1\n"
 ENDM
- N 19,10,12,5,21,3,7,0,15,21,5,3,5,9,6,9,25,7,10,5,16,26,6,0,4,5,18,7,8,3,22,8,5,22,23,11,28,1,2,20,2,1,2,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,1,9,2,28,5,29,26,6,9,6,29,0,14,7,13,5,0,5,14,4,8,3,5,27,24,0,4,5,18,7,8,1,2,6,9,1,0,22,17,18,15,8,0,14,7,13,5,0,4,5,18,7,8,1,2,6,2,20,1,0,14,7,13,19,0,3,7,3
+ N 19,10,12,5,21,3,7,0,15,21,5,3,5,9,6,9,25,7,10,5,16,26,6,0,4,5,18,7,8,3,22,8,5,22,23,11,28,1,2,20,2,1,2,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,1,9,2,30,5,31,26,6,9,6,29,0,14,7,13,5,0,5,14,4,8,3,5,27,24,0,4,5,18,7,8,1,2,6,9,1,0,22,17,18,15,8,0,14,7,13,5,0,4,5,18,7,8,1,2,6,2,20,1,0,14,7,13,19,0,3,7,3