MacOS x86 workflow

Author: Farah Khashman

.github/workflows/macos_ARM64_build.yaml

@@ -1,4 +1,4 @@
-name: C/C++ MacOS
+name: C/C++ MacOS ARM64
 
 on:
   push:

.github/workflows/macos_x86_build.yaml

@@ -0,0 +1,52 @@
+name: C/C++ MacOS x86
+
+on:
+  push:
+    branches: [master]
+    tags:
+       - 'v*'
+  release:
+   types: [published]
+  pull_request:
+    branches: [master]
+    types: [ready_for_review, opened, synchronize, reopened]
+    paths:
+      - .github/workflows/macos_ARM64_build.yaml
+      - ./App/**
+      - ./OREAnalytics/**
+      - '!./OREAnalytics/doc/**'
+      - ./OREData/**
+      - '!./OREData/doc/**'
+      - ./ORETest/**
+      - ./QuantExt/**
+      - '!./QuantExt/doc/**'
+      - CMakeLists.txt
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: macos-11
+    steps:
+    - uses: actions/checkout@v4
+    - name: get QuantLib
+      run: |
+        git submodule update --init
+    - name: Install Boost
+      run: |
+        curl -O -L https://boostorg.jfrog.io/artifactory/main/release/1.80.0/source/boost_1_80_0.tar.gz
+        tar xfz boost_1_80_0.tar.gz
+        cd boost_1_80_0
+        ./bootstrap.sh
+        ./b2 toolset=clang-darwin target-os=darwin architecture=x86 cxxflags="-arch x86_64" cflags="-arch x86_64" linkflags="-arch x86_64" abi=sysv binary-format=mach-o install
+    - name: cmake configure and build
+      run: |
+        mkdir build
+        cd build
+        cmake .. -DCMAKE_OSX_ARCHITECTURES=x86_64 -DORE_USE_ZLIB=ON -DBUILD_SHARED_LIBS=false -DORE_BUILD_DOC=OFF -DORE_BUILD_EXAMPLES=OFF -DORE_BUILD_TESTS=OFF -DORE_BUILD_APP=ON -DQL_BUILD_BENCHMARK=OFF -DQL_BUILD_EXAMPLES=OFF -DQL_BUILD_TEST_SUITE=OFF -DQL_ENABLE_SESSIONS=ON -DCMAKE_BUILD_TYPE=Release ..
+        cmake --build . -j4
+        cmake --install .
+    - name: Save executables as artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: ore-macos-x86
+        path: /Users/runner/work/Engine/Engine/build/App/ore