toolchain: remove LTO due to over optimization

target/snitch_cluster/sw/toolchain.mk

@@ -22,14 +22,11 @@ SW_INSTALL_DIR  ?= $(abspath $(MUSL_DIR)/../../../sw/deps/install/)
 # Compiler toolchain
 LLVM_BINROOT    ?= $(dir $(shell which riscv32-unknown-elf-clang))
 RISCV_CC        ?= $(LLVM_BINROOT)/clang
-RISCV_CXX 	    ?= $(LLVM_BINROOT)/clang++
 RISCV_LD        ?= $(LLVM_BINROOT)/ld.lld
 RISCV_AR        ?= $(LLVM_BINROOT)/llvm-ar
 RISCV_OBJCOPY   ?= $(LLVM_BINROOT)/llvm-objcopy
 RISCV_OBJDUMP   ?= $(LLVM_BINROOT)/llvm-objdump
 RISCV_DWARFDUMP ?= $(LLVM_BINROOT)/llvm-dwarfdump
-RISCV_RANLIB	?= $(LLVM_BINROOT)/llvm-ranlib
-RISCV_STRIP     ?= $(LLVM_BINROOT)/llvm-strip
 
 # Compiler flags
 RISCV_CFLAGS += $(addprefix -I,$(INCDIRS))
@@ -47,12 +44,9 @@ RISCV_CFLAGS += -fno-builtin-printf
 RISCV_CFLAGS += -fno-common
 RISCV_CFLAGS += -fopenmp
 
-RISCV_CFLAGS += -flto=thin
-RISCV_CFLAGS += -ffunction-sections
-RISCV_CFLAGS += -Wextra
-RISCV_CFLAGS += -static
-RISCV_CFLAGS += -mllvm -enable-misched=false
-RISCV_CFLAGS += -mno-relax
+# TODO: check why the LTO flags optimizes the CBSS section away
+# RISCV_CFLAGS += -flto=thin
+
 RISCV_CFLAGS += -ftls-model=local-exec
 RISCV_CFLAGS += -nostdinc
 
@@ -65,16 +59,10 @@ endif
 RISCV_LDFLAGS += -fuse-ld=$(RISCV_LD)
 RISCV_LDFLAGS += -nostartfiles
 RISCV_LDFLAGS += -lm
-RISCV_LDFLAGS += -static
-RISCV_LDFLAGS += -mcpu=snitch -nostartfiles -fuse-ld=lld -Wl,--image-base=0x80000000
-RISCV_LDFLAGS += -Wl,-z,norelro
-RISCV_LDFLAGS += -Wl,--gc-sections
-RISCV_LDFLAGS += -Wl,--no-relax
-RISCV_LDFLAGS += -Wl,--verbose
 # musl specific flags
 RISCV_LDFLAGS += -L$(SW_INSTALL_DIR)/lib
 RISCV_LDFLAGS += -nostdinc
-RISCV_LDFLAGS += -flto=thin
+# RISCV_LDFLAGS += -flto=thin
 
 # Archiver flags
 RISCV_ARFLAGS = rcs