[InstrProf][NFC] Fix a few typos in code comments.

Author: snehasish

llvm/include/llvm/ProfileData/InstrProf.h

@@ -205,9 +205,9 @@ StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName,
                                    StringRef FileName = "<unknown>");
 
 /// Given a vector of strings (function PGO names) \c NameStrs, the
-/// method generates a combined string \c Result thatis ready to be
+/// method generates a combined string \c Result that is ready to be
 /// serialized.  The \c Result string is comprised of three fields:
-/// The first field is the legnth of the uncompressed strings, and the
+/// The first field is the length of the uncompressed strings, and the
 /// the second field is the length of the zlib-compressed string.
 /// Both fields are encoded in ULEB128.  If \c doCompress is false, the
 ///  third field is the uncompressed strings; otherwise it is the

llvm/include/llvm/ProfileData/InstrProfReader.h

@@ -205,7 +205,7 @@ class TextInstrProfReader : public InstrProfReader {
 
 /// Reader for the raw instrprof binary format from runtime.
 ///
-/// This format is a raw memory dump of the instrumentation-baed profiling data
+/// This format is a raw memory dump of the instrumentation-based profiling data
 /// from the runtime.  It has no index.
 ///
 /// Templated on the unsigned type whose size matches pointers on the platform

llvm/lib/ProfileData/ProfileSummaryBuilder.cpp

@@ -192,7 +192,7 @@ SampleProfileSummaryBuilder::computeSummaryForProfiles(
   // into many copies each representing the CFG profile of a particular calling
   // context. That makes the count distribution looks more flat as we now have
   // more function profiles each with lower counts, which in turn leads to lower
-  // hot thresholds. To compensate for that, by defauly we merge context
+  // hot thresholds. To compensate for that, by default we merge context
   // profiles before computing profile summary.
   if (UseContextLessSummary || (sampleprof::FunctionSamples::ProfileIsCS &&
                                 !UseContextLessSummary.getNumOccurrences())) {