feat: implement CIE 9.1 text file handling (OPENFILE/READFILE/WRITEFILE/CLOSEFILE/EOF)

Front end: OPENFILE/READFILE/WRITEFILE/CLOSEFILE plus reserved mode
keywords READ/WRITE/APPEND (RANDOM reserved with a dedicated
not-implemented error); statement nodes in new FileAST.h, parsing in new
ParserFile.cc; EOF joins the Builtins table as the 12th builtin and
CallExprAST now carries a line number for its runtime diagnostics.

Runtime: new FileHandler (StringHandler-shaped leaf) lazily synthesizes
internal __cps_file_* helper functions and a 16-slot open-file table
keyed by filename content (strcmp — STRING '=' is pointer identity).
EOF is an fgetc/ungetc peek; READFILE grows a malloc/realloc line buffer
and strips a trailing CR; fopen uses text modes so mingw-w64 line
translation works. File-free programs get byte-identical IR. All misuse
(not open, wrong mode, reopen, fopen failure, read past EOF, table full)
dies with the existing "[Fatal] line N:" pattern via a new
RuntimeCheck::emitErrorAndExit overload taking runtime printf args.

Also fixes a pre-existing ArithmeticHandler hole surfaced by adversarial
review: mixed-width integer operands (i1 BOOLEAN / i8 CHAR vs i64) now
widen via ZExt instead of emitting invalid IR, and remaining type
mismatches get a clean diagnostic; -EOF(f) and -IS_NUM(x) compile.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/CodeGen/RuntimeCheck.cc b/lib/CodeGen/RuntimeCheck.cc
index d51d78a..c2ced87 100644
--- a/lib/CodeGen/RuntimeCheck.cc
+++ b/lib/CodeGen/RuntimeCheck.cc
@@ -27,8 +27,12 @@ void RuntimeCheck::setupExternalFunctions() {
 }
 
 void RuntimeCheck::emitErrorAndExit(Value *Condition, Value *Msg, int Line) {
+    emitErrorAndExit(Condition, Msg, {ConstantInt::get(TheContext, APInt(32, Line))});
+}
+
+void RuntimeCheck::emitErrorAndExit(Value *Condition, Value *Msg, ArrayRef<Value *> FmtArgs) {
     Function *TheFunction = Builder.GetInsertBlock()->getParent();
-    
+
     BasicBlock *FailBB = BasicBlock::Create(TheContext, "check_fail", TheFunction);
     BasicBlock *ContBB = BasicBlock::Create(TheContext, "check_cont", TheFunction);
 
@@ -37,7 +41,7 @@ void RuntimeCheck::emitErrorAndExit(Value *Condition, Value *Msg, int Line) {
     Builder.SetInsertPoint(FailBB);
     std::vector<Value*> PrintArgs;
     PrintArgs.push_back(Msg);
-    PrintArgs.push_back(ConstantInt::get(TheContext, APInt(32, Line)));
+    PrintArgs.insert(PrintArgs.end(), FmtArgs.begin(), FmtArgs.end());
     Builder.CreateCall(PrintfFunc, PrintArgs);
 
     Builder.CreateCall(ExitFunc, ConstantInt::get(TheContext, APInt(32, 1)));