core/irrt: comment build.rs & move irrt to nac3core/irrt

Achieved through defining all the needed Exception ID constants at link
time.

Secondly, since `Exception` is `size_t` dependent, `__nac3_raise()`
takes an opaque pointer to `Exception`.

@@ -0,0 +1,3 @@
+BasedOnStyle: Microsoft

@@ -33,6 +33,7 @@ use inkwell::{
     OptimizationLevel,
 };
 use itertools::Itertools;
+use nac3core::codegen::irrt::setup_irrt_exceptions;

@@ -0,0 +1,4 @@
+#include <irrt/exception.hpp>
+#include <irrt/int_types.hpp>
+#include <irrt/math_util.hpp>
+#include <irrt/original.hpp>

@@ -0,0 +4,4 @@
+
+template <typename SizeT> struct CSlice
+{
+    uint8_t *base;

@@ -0,0 +7,4 @@
+/**
+ * @brief Implementation of `strlen()`.
+ */
+uint32_t length(const char *str)

@@ -0,0 +10,4 @@
+#define raise_debug_assert(SizeT, msg, param1, param2, param3)                                                         \
+    raise_exception(SizeT, EXN_ASSERTION_ERROR, "IRRT debug assert failed: " msg, param1, param2, param3);
+
+#define debug_assert_eq(SizeT, lhs, rhs)                                                                               \

@@ -0,0 +45,4 @@
+    int64_t params[3];
+};
+
+const int64_t NO_PARAM = 0;

@@ -0,0 +53,4 @@
+{
+    Exception<SizeT> e = {
+        .id = id,
+        .filename = {.base = (uint8_t *)filename, .len = (int32_t)cstr::length(filename)},

@@ -0,0 +57,4 @@
+        .line = line,
+        .column = 0,
+        .function = {.base = (uint8_t *)function, .len = (int32_t)cstr::length(function)},
+        .msg = {.base = (uint8_t *)msg, .len = (int32_t)cstr::length(msg)},

@@ -0,0 +62,4 @@
+    e.params[0] = param0;
+    e.params[1] = param1;
+    e.params[2] = param2;
+    __nac3_raise((void *)&e);

@@ -0,0 +1,372 @@
+#pragma once

@@ -931,1 +931,4 @@
 }
+
+/// Initialize all global `EXN_*` exception IDs in IRRT with the [`SymbolResolver`].
+pub fn setup_irrt_exceptions<'ctx>(

@@ -14,6 +14,7 @@ use inkwell::{
     memory_buffer::MemoryBuffer, passes::PassBuilderOptions, support::is_multithreaded, targets::*,
     OptimizationLevel,
 };
+use nac3core::codegen::irrt::setup_irrt_exceptions;

@@ -0,0 +52,4 @@
+                             int64_t param0, int64_t param1, int64_t param2)
+{
+    Exception<SizeT> e = {
+        .id = id,

@@ -0,0 +11,4 @@
+    raise_exception(SizeT, EXN_ASSERTION_ERROR,                                \
+                    "IRRT debug assert failed: " msg, param1, param2, param3);
+
+#define debug_assert_eq(SizeT, lhs, rhs) if constexpr (IRRT_DEBUG_ASSERT_BOOL)