Create jl_clear_coverage_data to dynamically reset coverage (#54358)

There are some use-cases that would benefit from being able to
reset the code coverage information during runtime. This creates
the function `jl_clear_coverage_data` to reset the `coverageData`
global.

Author: MilesCranmer

src/coverage.cpp

@@ -77,26 +77,37 @@ JL_DLLEXPORT uint64_t *jl_malloc_data_pointer(StringRef filename, int line)
     return allocLine(mallocData[filename], line);
 }
 
-// Resets the malloc counts.
-extern "C" JL_DLLEXPORT void jl_clear_malloc_data(void)
+static void clear_log_data(logdata_t &logData, int resetValue)
 {
-    logdata_t::iterator it = mallocData.begin();
-    for (; it != mallocData.end(); it++) {
+    logdata_t::iterator it = logData.begin();
+    for (; it != logData.end(); it++) {
         SmallVector<logdata_block*, 0> &bytes = (*it).second;
         SmallVector<logdata_block*, 0>::iterator itb;
         for (itb = bytes.begin(); itb != bytes.end(); itb++) {
             if (*itb) {
                 logdata_block &data = **itb;
                 for (int i = 0; i < logdata_blocksize; i++) {
                     if (data[i] > 0)
-                        data[i] = 1;
+                        data[i] = resetValue;
                 }
             }
         }
     }
     jl_gc_sync_total_bytes(0);
 }
 
+// Resets the malloc counts.
+extern "C" JL_DLLEXPORT void jl_clear_malloc_data(void)
+{
+    clear_log_data(mallocData, 1);
+}
+
+// Resets the code coverage
+extern "C" JL_DLLEXPORT void jl_clear_coverage_data(void)
+{
+    clear_log_data(coverageData, 0);
+}
+
 static void write_log_data(logdata_t &logData, const char *extension)
 {
     std::string base = std::string(jl_options.julia_bindir);