7689 - permit metadata on Mu literal integers

Metadata is always ignored. It's purely for documentation purposes. But
as long as Mu has no named constants it's starting to feel increasingly
essential.

I'm still not going to bother to add metadata to other parts of the language.
Let's see if we need them. Even though it's a little warty that the rules
vary throughout the stack:

  - bare SubX: metadata everywhere
  - SubX with syntax sugar: no metadata in calls or addressing-mode sigil-expressions
  - Mu: metadata only for literal integers

apps/mu.subx

@@ -2420,6 +2420,34 @@ test-convert-invalid-literal:
     5d/pop-to-ebp
     c3/return
 
+test-convert-valid-literal-with-metadata:
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # setup
+    (clear-stream _test-input-stream)
+    (clear-stream $_test-input-buffered-file->buffer)
+    (clear-stream _test-output-stream)
+    (clear-stream $_test-output-buffered-file->buffer)
+    #
+    (write _test-input-stream "fn foo {\n")
+    (write _test-input-stream "  var x/eax: int <- copy 1/abc\n")
+    (write _test-input-stream "}\n")
+    # convert
+    (convert-mu _test-input-buffered-file _test-output-buffered-file Stderr 0)
+    (flush _test-output-buffered-file)
+#?     # dump _test-output-stream {{{
+#?     (write 2 "^")
+#?     (write-stream 2 _test-output-stream)
+#?     (write 2 "$\n")
+#?     (rewind-stream _test-output-stream)
+#?     # }}}
+    # no errors
+    # . epilogue
+    89/<- %esp 5/r32/ebp
+    5d/pop-to-ebp
+    c3/return
+
 test-local-var-in-mem-has-no-initializer:
     # . prologue
     55/push-ebp
@@ -16865,6 +16893,7 @@ $test-function-header-with-multiple-args-and-outputs:out1:
 #   x/eax: int
 #   x/eax: int,
 # ignores at most one trailing comma
+# does not support other, non-register metadata
 # WARNING: modifies name
 parse-var-with-type:  # name: (addr slice), first-line: (addr stream byte), out: (addr handle var), fn-name: (addr array byte), err: (addr buffered-file), ed: (addr exit-descriptor)
     # pseudocode:
@@ -19680,6 +19709,7 @@ $new-var:end:
     5d/pop-to-ebp
     c3/return
 
+# WARNING: modifies name
 new-literal-integer:  # ad: (addr allocation-descriptor), name: (addr slice), out: (addr handle var), fn: (addr function), err: (addr buffered-file), ed: (addr exit-descriptor)
     # . prologue
     55/push-ebp
@@ -19687,6 +19717,9 @@ new-literal-integer:  # ad: (addr allocation-descriptor), name: (addr slice), ou
     # . save registers
     50/push-eax
     51/push-ecx
+    # first strip out metadata
+    8b/-> *(ebp+0xc) 1/r32/ecx
+    (next-token-from-slice *ecx *(ecx+4) 0x2f *(ebp+0xc))
     # if (!is-hex-int?(name)) abort
     (is-hex-int? *(ebp+0xc))  # => eax
     3d/compare-eax-and 0/imm32/false