Refactor LLVM JIT (#1613)

Refactor LLVM JIT for some purposes:
- To simplify the source code of JIT compilation
- To simplify the JIT modes
- To align with LLVM latest changes
- To prepare for the Multi-tier JIT compilation, refer to #1302

The changes mainly include:
- Remove the MCJIT mode, replace it with ORC JIT eager mode
- Remove the LLVM legacy pass manager (only keep the LLVM new pass manager)
- Change the lazy mode's LLVM module/function binding:
  change each function in an individual LLVM module into all functions in a single LLVM module
- Upgraded ORC JIT to ORCv2 JIT to enable lazy compilation

Refer to #1468

tests/wamr-test-suites/test_wamr.sh

@@ -173,10 +173,18 @@ readonly FAST_INTERP_COMPILE_FLAGS="\
 
 # jit: report linking error if set COLLECT_CODE_COVERAGE,
 #      now we don't collect code coverage of jit type
-readonly JIT_COMPILE_FLAGS="\
+readonly ORC_EAGER_JIT_COMPILE_FLAGS="\
     -DWAMR_BUILD_TARGET=${TARGET} \
     -DWAMR_BUILD_INTERP=0 -DWAMR_BUILD_FAST_INTERP=0 \
     -DWAMR_BUILD_JIT=1 -DWAMR_BUILD_AOT=1 \
+    -DWAMR_BUILD_LAZY_JIT=0 \
+    -DWAMR_BUILD_SPEC_TEST=1"
+
+readonly ORC_LAZY_JIT_COMPILE_FLAGS="\
+    -DWAMR_BUILD_TARGET=${TARGET} \
+    -DWAMR_BUILD_INTERP=0 -DWAMR_BUILD_FAST_INTERP=0 \
+    -DWAMR_BUILD_JIT=1 -DWAMR_BUILD_AOT=1 \
+    -DWAMR_BUILD_LAZY_JIT=1 \
     -DWAMR_BUILD_SPEC_TEST=1"
 
 readonly AOT_COMPILE_FLAGS="\
@@ -196,7 +204,8 @@ readonly FAST_JIT_COMPILE_FLAGS="\
 readonly COMPILE_FLAGS=(
         "${CLASSIC_INTERP_COMPILE_FLAGS}"
         "${FAST_INTERP_COMPILE_FLAGS}"
-        "${JIT_COMPILE_FLAGS}"
+        "${ORC_EAGER_JIT_COMPILE_FLAGS}"
+        "${ORC_LAZY_JIT_COMPILE_FLAGS}"
         "${AOT_COMPILE_FLAGS}"
         "${FAST_JIT_COMPILE_FLAGS}"
     )
@@ -600,9 +609,16 @@ function trigger()
                     continue
                 fi
 
-                echo "work in jit mode"
-                # jit
-                BUILD_FLAGS="$JIT_COMPILE_FLAGS $EXTRA_COMPILE_FLAGS"
+                echo "work in orc jit eager compilation mode"
+                BUILD_FLAGS="$ORC_EAGER_JIT_COMPILE_FLAGS $EXTRA_COMPILE_FLAGS"
+                build_iwasm_with_cfg $BUILD_FLAGS
+                build_wamrc
+                for suite in "${TEST_CASE_ARR[@]}"; do
+                    $suite"_test" jit
+                done
+
+                echo "work in orc jit lazy compilation mode"
+                BUILD_FLAGS="$ORC_EAGER_JIT_COMPILE_FLAGS $EXTRA_COMPILE_FLAGS"
                 build_iwasm_with_cfg $BUILD_FLAGS
                 build_wamrc
                 for suite in "${TEST_CASE_ARR[@]}"; do