Move requirements-iree-*.txt to top level. (#765)

This is prep work for #760.

I also considered putting the files under `build_tools/` or `shark-ai/`,
but we already have a few requirements files in the repository root.
Still not as many as https://github.com/vllm-project/vllm though 😛.

.github/workflows/ci-libshortfin.yml

@@ -101,12 +101,12 @@ jobs:
         cache: "pip"
         cache-dependency-path: |
           'shortfin/requirements-tests.txt'
-          'shortfin/requirements-iree-compiler.txt'
+          'requirements-iree-pinned.txt'
     - name: Install Python packages
       working-directory: ${{ env.LIBSHORTFIN_DIR }}
       run: |
         pip install -r requirements-tests.txt
-        pip install -r requirements-iree-compiler.txt
+        pip install -r ../requirements-iree-pinned.txt
         pip freeze
 
     - name: Build shortfin

.github/workflows/ci-sdxl.yaml

@@ -65,7 +65,7 @@ jobs:
       working-directory: ${{ env.LIBSHORTFIN_DIR }}
       run: |
         pip install -r requirements-tests.txt
-        pip install -r requirements-iree-compiler.txt
+        pip install -r ../requirements-iree-pinned.txt
         pip freeze
 
     - name: Install shortfin

.github/workflows/ci_linux_x64_asan-libshortfin.yml

@@ -124,7 +124,7 @@ jobs:
       run: |
         eval "$(pyenv init -)"
         pip install -r requirements-tests.txt
-        pip install -r requirements-iree-compiler.txt
+        pip install -r ../requirements-iree-pinned.txt
         pip freeze
 
     - name: Save Python dependencies cache

requirements-iree-pinned.txt

@@ -0,0 +1,10 @@
+# Pinned versions of IREE dependencies.
+
+# Keep these versions synced with SHORTFIN_IREE_GIT_TAG in shortfin/CMakeLists.txt
+--pre
+--find-links https://iree.dev/pip-release-links.html
+iree-base-compiler==3.1.0rc20241204
+iree-base-runtime==3.1.0rc20241204
+
+# TODO(#760): include iree-turbine in this requirements file too?
+# iree-turbine==3.1.0rc20241205

requirements-iree-unpinned.txt

@@ -0,0 +1,9 @@
+# Unpinned versions of IREE dependencies.
+
+--pre
+--find-links https://iree.dev/pip-release-links.html
+iree-base-compiler
+iree-base-runtime
+
+# TODO(#760): include iree-turbine in this requirements file too?
+# iree-turbine

shortfin/CMakeLists.txt

@@ -43,8 +43,10 @@ endif()
 add_compile_options("$<$<C_COMPILER_ID:MSVC>:/utf-8>")
 add_compile_options("$<$<CXX_COMPILER_ID:MSVC>:/utf-8>")
 
-# Pins
-# Keep in sync with requirements-iree-compiler.txt.
+# Version pins for dependencies.
+# Prefer to keep the IREE git tag synced with the Python package version in the
+# requirements-iree-pinned.txt file. At a minimum, the compiler from those
+# packages must be compatible with the runtime at this source ref.
 set(SHORTFIN_IREE_GIT_TAG "iree-3.1.0rc20241220")
 
 # build options