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, 51 insertions, 0 deletions

diff --git a/chapter25/docs/examples/FileIO.smp b/chapter25/docs/examples/FileIO.smp
new file mode 100644
index 00000000..29f037bd
--- /dev/null
+++ b/chapter25/docs/examples/FileIO.smp
@@ -0,0 +1,51 @@
+// -*- mode: java;  -*-
+
+// An implementation of
+// https://sampleprograms.io/projects/file-input-output/
+
+val FILE = "output.txt";
+
+val main = { u8[~][] args ->
+    var str = new sys.aryu8();
+    str.addAry("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.\n");
+    str.addAry("Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.\n");
+    str.addAry("Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.\n");
+    str.addAry("Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.\n");
+
+    // Create
+    i32 fd = sys.io.create(FILE);
+    if( fd == -1 ) return _error();
+    // Write
+    int wrote = sys.io.writeOff(fd,str.buf,0,str.len);
+    if( wrote == -1 ) return _error();
+    if( wrote != str.len ) return _error2(-2);
+    // Close
+    if( sys.io.close(fd) != 0 ) return _error();
+
+    // Open
+    i32 fd2 = sys.io.open(FILE);
+    if( fd2 == -1 ) return _error();
+    // Read
+    var got = sys.io.read(fd2);
+    if( got# != str.len ) return _error2(-3);
+    // Close
+    if( sys.io.close(fd2) != 0 ) return _error();
+
+    // Check contents are equal
+    if( sys.ary.cmp(got,0,str.buf,0,str.len) )
+        return _error2(-4);
+
+    // Remove
+    if( sys.io.remove(FILE) != 0 ) return _error();
+
+    sys.io.p("File I/O succeeded\n");
+    return 0;
+};
+
+val _error2 = { i32 errno ->
+    sys.io.remove(FILE);
+    new sys.aryu8().addAry("Failed with error code ").num(errno).add('\n').write(sys.libc.STDERR);
+    sys.libc._exit(errno);
+};
+
+val _error = { -> _error2(sys.libc.errno); };