Squashed commit of the following:

commit c05d7df4f9c90984d2c04126772be3fee1d81fd1
Author: Cliff Click <cliffc@acm.org>
Date:   Thu Aug 20 10:52:58 2026 -0700

    Fix local frefs, deferred inlining, and sys FileIO support

    - Defer non-trivial inlining out of CallEnd idealization and run it from IterPeeps after normal peepholes reach a fixed point.
    - Keep forward refs local to their lexical scope, promote them outward on scope pop, and track created FRefNodes directly for dependency  discovery.
    - Preserve loop scope shape when frefs are first seen inside loop bodies.
    - Treat frefs as final constants from creation and force lazy self lookups before implicit calls.
    - Reset imported pointer/struct types conservatively for post-parse Iter.
    - Pin Start-owned global machine value chains and clone global constants per function during GCM.
    - Improve late ASM printing before encoding and namespace constant-pool symbols.
    - Add optional regalloc function-local edge verifier and improve empty-mask splitting for multi-def/fixed-register LRGs.
    - Add sys array compare, safer array copy bounds, libc open/creat/close/unlink bindings, aryu8.str0, and higher-level sys.io file operations.
    - Add docs/examples/FileIO.smp and a Chapter25 FileIO test.
    - Update spill/code-size goldens after the allocator and scheduling changes.

commit ef5316979732ac118612d310b75923c8f59ecdc1
Author: Cliff Click <cliffc@acm.org>
Date:   Fri Aug 14 16:29:56 2026 -0700

    Dijkstra uses bitset.

    TestC.exec for repeated test runs with different stdins.
    Support &= and |= op-update forms.

commit 728a527587f19bb49860f02ae5ac5968ab01ae33
Author: Cliff Click <cliffc@acm.org>
Date:   Fri Aug 14 12:13:28 2026 -0700

    Fix live demo

commit e4c069b9ef2cbfafe28d8edfcbff55396cde085e
Author: Cliff Click <cliffc@acm.org>
Date:   Fri Aug 14 09:52:24 2026 -0700

    Update Dijkstra.smp

commit b8015739b4056e3f7a715a030e846a441021a9f1
Author: Cliff Click <cliffc@acm.org>
Date:   Fri Aug 14 09:41:17 2026 -0700

    Better looking Dijkstra

commit 7cce587804c6169b24829e0b5bdc10be94357a31
Author: Cliff Click <cliffc@acm.org>
Date:   Fri Aug 14 09:33:33 2026 -0700

    Fix CmpMemX86 encoding

    Use sys.aryu8 for number printing

commit 310b5d8c9978a3b09622a4b89dac97f0e5e6f3fb
Author: Cliff Click <cliffc@acm.org>
Date:   Fri Aug 14 09:04:58 2026 -0700

    Progress dijlstra

    Fix NotX86 encoding.  Allow Not-sinking through Phis; the Nots both take Scalar and might take different types (ptr vs int).  Better guard installing during && || opers.
    Drop the csv parse flavor in sys lib.

commit 5917d5322521dd5e762c4698d34e5d7ac9b3a37f
Author: Cliff Click <cliffc@acm.org>
Date:   Thu Aug 13 14:44:12 2026 -0700

    missed

commit da35ad4d8a330559a21c04ae6326536e0fd62c48
Author: Cliff Click <cliffc@acm.org>
Date:   Thu Aug 13 14:43:42 2026 -0700

    Major cleanup of allocation

    All the graph-gen is moved to the <ctor> declaration and not at the alloc site.

commit c4223216099ccbc526d282bb263972532d48c5b2
Author: Cliff Click <cliffc@acm.org>
Date:   Thu Aug 13 13:26:01 2026 -0700

    Some work from Dykstra (more coming)

commit a03bc567f61dc7e4355e453ee4be16ac2528d1ab
Author: Cliff Click <cliffc@acm.org>
Date:   Thu Aug 13 09:32:55 2026 -0700

    Spill correctness and improvements

    Had the callee-save pick-risky backwards vs cloneables.

commit 2d306e4430225f916cb7fb999f4926e52f6fb70a
Author: Cliff Click <cliffc@acm.org>
Date:   Wed Aug 12 19:40:04 2026 -0700

    Tighter parser handling of missing fields

    Bug fix add libc.errno, read can return -1, sys.ary exists

commit b7eeefda4cafa1e86153170dca6f13d45ef63f69
Author: Cliff Click <cliffc@acm.org>
Date:   Wed Aug 12 16:22:48 2026 -0700

    Printer improvements

commit 8b9112226f1d2d1c843b080eecefe0d5ddc1f8cf
Author: Cliff Click <cliffc@acm.org>
Date:   Wed Aug 12 15:30:46 2026 -0700

    Remove GLB

commit ae566f5c610b9c30831906d3f024901d8930a227
Author: Cliff Click <cliffc@acm.org>
Date:   Wed Aug 12 14:38:51 2026 -0700

    Add Capitalize example

    Rename Ary to ary.
    Fix bug || carrying state along.
    Fix bug load-array removing control.
    Add sys.char tolower/upper

1 files changed, 30 insertions, 8 deletions

diff --git a/chapter25/src/main/smp/sys/aryu8.smp b/chapter25/src/main/smp/sys/aryu8.smp
index 0ce4bd23..186a45a3 100644
--- a/chapter25/src/main/smp/sys/aryu8.smp
+++ b/chapter25/src/main/smp/sys/aryu8.smp
@@ -5,9 +5,7 @@ struct aryu8 {
     u32 !len = 0;
     u8[] !buf;
 
-    new aryu8 = { u8[] b ->
-        buf = b;
-    };
+    new aryu8 = { -> buf = new u8[1]; };
 
     // Grow as needed
     val _grow = { int len2 ->
@@ -15,7 +13,7 @@ struct aryu8 {
         int newlen = buf# * 2;
         while( len+len2 >= newlen ) newlen *= 2;
         u8[] !buf2 = new u8[newlen];
-        Ary.copy(buf2,0,buf,0,buf#);
+        ary.copy(buf2,0,buf,0,buf#);
         buf = buf2;
         self;
     };
@@ -29,10 +27,10 @@ struct aryu8 {
     };
 
     // Add all of a plain array to the aryu8
-    val addAry = { u8[~] ary ->
-        _grow(ary#);
-        Ary.copy(buf,len,ary,0,ary#);
-        len += ary#;
+    val addAry = { u8[~] xs ->
+        _grow(xs#);
+        ary.copy(buf,len,xs,0,xs#);
+        len += xs#;
         self;
     };
 
@@ -64,3 +62,27 @@ struct aryu8 {
         libc.write(fd,ptr,len);
     };
 };
+
+
+// Parse one integer, ignore trailing data; returns 0 with an empty string.
+// If you want a more robust parsing, use the `scan` class
+val atoi = { u8[~] str ->
+    int x = 0;
+    while( x < str# && str[x] <= ' ' ) x++;
+    if( x == str# ) return 0;
+    bool neg = false;
+    if( str[x]=='-' ) { neg=true; x++; }
+    i64 n = 0;
+    while( x < str# && '0' <= str[x] <= '9' )
+        n = n*10 + str[x++]-'0';
+    return neg ? -n : n;
+};
+
+// Zero-terminate string for libc strings.  No error checking, just copies and
+// appends a zero.
+{ u8[~] -> u8[] } str0 = { u8[~] str ->
+  u8[] !strz = new u8[str#+1];
+  ary.copy(strz,0,str,0,str#);
+  strz[str#] = '\0';
+  strz;
+};