feat(asm): symbol-valued DATA, division slash in symbols and plain semicolons

Assisted-by: GLM 5.3 Flash

lexer/lexer.go

@@ -16,8 +16,16 @@ import (
 	"sourcedock.dev/petrbalvin/gasm-devkit/token"
 )
 
-// middleDot is the Plan 9 symbol separator (U+00B7), used in ·funcName(SB).
-const middleDot = '\u00B7'
+const (
+	// middleDot is the Plan 9 symbol separator (U+00B7), used in
+	// ·funcName(SB): it stands for the period between package path and name.
+	middleDot = '\u00B7'
+	// divisionSlash is the Plan 9 path separator (U+2215), used inside the
+	// package path of a symbol: internal∕runtime∕atomic·Xchg.  Like the
+	// middle dot it is an identifier character, so a package path containing
+	// it lexes as one name; the ordinary slash (U+002F) stays punctuation.
+	divisionSlash = '\u2215'
+)
 
 // Lexer scans a source string one token at a time.
 type Lexer struct {
@@ -460,7 +468,7 @@ func isHexDigit(r rune) bool {
 }
 
 func isIdentStart(r rune) bool {
-	return r == '_' || r == middleDot || unicode.IsLetter(r)
+	return r == '_' || r == middleDot || r == divisionSlash || unicode.IsLetter(r)
 }
 
 func isIdentChar(r rune) bool {