[libc] Fix fixed point detection and add compile option. (#81788)

Author: lntue

libc/cmake/modules/LLVMLibCObjectRules.cmake

@@ -49,6 +49,10 @@ function(_get_common_compile_options output_var flags)
       list(APPEND compile_options "-ffreestanding")
     endif()
 
+    if(LIBC_COMPILER_HAS_FIXED_POINT)
+      list(APPEND compile_options "-ffixed-point")
+    endif()
+
     list(APPEND compile_options "-fno-builtin")
     list(APPEND compile_options "-fno-exceptions")
     list(APPEND compile_options "-fno-lax-vector-conversions")

libc/cmake/modules/compiler_features/check_fixed_point.cpp

@@ -1,4 +1,4 @@
-#include "include/llvm-libc-macross/stdfix_macros.h"
+#include "include/llvm-libc-macros/stdfix-macros.h"
 
 #ifndef LIBC_COMPILER_HAS_FIXED_POINT
 #error unsupported

libc/test/UnitTest/CMakeLists.txt

@@ -31,6 +31,9 @@ function(add_unittest_framework_library name)
     if(TARGET libc.src.time.clock)
       target_compile_definitions(${lib} PRIVATE TARGET_SUPPORTS_CLOCK)
     endif()
+    if(LIBC_COMPILER_HAS_FIXED_POINT)
+      target_compile_options(${lib} PUBLIC -ffixed-point)
+    endif()
   endforeach()
   target_include_directories(${name}.hermetic PRIVATE ${LIBC_BUILD_DIR}/include)
   target_compile_options(${name}.hermetic