llvm.cmake: remove additional compiler options

This brings this file in-line with gcc.cmake which also doesn't add any
compiler flags that affect build behavior. This leaves other layers of
the build system to be able to set flags if necessary without inheriting
a large number by default.

Signed-off-by: Kent McLeod <[email protected]>

Author: kent-mcleod

llvm.cmake

@@ -19,9 +19,6 @@ set(CMAKE_ASM_COMPILER "clang")
 set(CMAKE_ASM_COMPILER_ID Clang)
 set(CMAKE_ASM_COMPILER_TARGET ${TRIPLE})
 
-string(APPEND asm_common_flags " -Wno-unused-command-line-argument")
-string(APPEND asm_common_flags " -fno-integrated-as")
-
 set(CMAKE_C_COMPILER "clang")
 set(CMAKE_C_COMPILER_ID Clang)
 set(CMAKE_C_COMPILER_TARGET ${TRIPLE})
@@ -30,16 +27,6 @@ set(CMAKE_CXX_COMPILER "clang++")
 set(CMAKE_CXX_COMPILER_ID Clang)
 set(CMAKE_CXX_COMPILER_TARGET ${TRIPLE})
 
-string(APPEND c_common_flags " -Wno-sizeof-pointer-div")
-string(APPEND c_common_flags " -Qunused-arguments")
-string(APPEND c_common_flags " -Wno-constant-logical-operand")
-if(NOT ("${TRIPLE}" MATCHES "^riscv"))
-    string(APPEND c_common_flags " -fno-integrated-as")
-endif()
-# clang 11 has a regression in GlobalISel (only used at -O0) affecting the syscall
-# stubs in libsel4runtime; see https://reviews.llvm.org/D83384#2189132
-string(APPEND c_common_flags " -fno-experimental-isel")
-
 set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)