Use alternate method to inject COMPILER_ARGS for N64 EGCS compilers (#1709)

* Use alternate method to inject COMPILER_ARGS for N64 EGCS compilers

* golf

* gpt feedback

* handle empty flags

* Move COMPILER_FLAGS after the hardcoded flags

Author: mkst

backend/coreapp/compilers.py

@@ -930,16 +930,25 @@ def available_platforms() -> List[Platform]:
     '&& python3 "${COMPILER_DIR}"/modern-asn64.py mips-linux-gnu-as "$OUTPUT".s -G0 -EB -mtune=vr4300 -march=vr4300 -mabi=32 -O1 --no-construct-floats -o "$OUTPUT"',
 )
 
+# Python alternative to the printf/xargs approach for quoted flags
+PYTHON_SHLEX = """[[ -n "${COMPILER_FLAGS}" ]] && mapfile -t FLAGS < <(python3 -c "import shlex,sys; print(*shlex.split(sys.argv[1]), sep='\\n')" "${COMPILER_FLAGS}"); """
+
 EGCS1124 = GCCCompiler(
     id="egcs_1.1.2-4",
     platform=N64,
-    cc='printf "%s" "${COMPILER_FLAGS}" | COMPILER_PATH="${COMPILER_DIR}" xargs -- "${COMPILER_DIR}"/mips-linux-gcc -c -G 0 -fno-PIC -mgp32 -mfp32 -mcpu=4300 -nostdinc "${INPUT}" -o "${OUTPUT}"',
+    cc=(
+        PYTHON_SHLEX
+        + 'COMPILER_PATH="${COMPILER_DIR}" "${COMPILER_DIR}/mips-linux-gcc" -c -G 0 -fno-PIC -mgp32 -mfp32 -mcpu=4300 -nostdinc "${FLAGS[@]}" "${INPUT}" -o "${OUTPUT}"'
+    ),
 )
 
 EGCS1124C = GCCCompiler(
     id="egcs_1.1.2-4c",
     platform=N64,
-    cc='printf "%s" "${COMPILER_FLAGS}" | COMPILER_PATH="${COMPILER_DIR}" xargs -- "${COMPILER_DIR}"/gcc -c -G 0 -fno-PIC -mgp32 -mfp32 -mcpu=4300 -nostdinc "${INPUT}" -o "${OUTPUT}"',
+    cc=(
+        PYTHON_SHLEX
+        + 'COMPILER_PATH="${COMPILER_DIR}" "${COMPILER_DIR}/gcc" -c -G 0 -fno-PIC -mgp32 -mfp32 -mcpu=4300 -nostdinc "${FLAGS[@]}" "${INPUT}" -o "${OUTPUT}"'
+    ),
 )
 
 GCC440MIPS64ELF = GCCCompiler(